Cyclonic vacuum cleaner

ABSTRACT

A surface cleaning apparatus comprises a dirt inlet, a handle, a cyclonic cleaning unit comprising a plurality of cyclones and at least one dirt collection chamber, each of the plurality of cyclones having an outer wall, an interior, a fluid inlet downstream from the dirt inlet and a fluid outlet, the at least one dirt collection chamber having an outer wall and an interior, wherein the surface cleaning apparatus is constructed such that the interior of the at least one dirt collection chamber is visible from a position exterior to the surface cleaning apparatus and a fluid flow motor. The surface cleaning apparatus may have a filter with a housing that is at least partially transparent.

FIELD OF THE INVENTION

In one aspect, this invention relates to a cyclonic surface cleaningapparatus, such as a vacuum cleaner that has a plurality of cyclones inparallel having at least one dirt collection chamber wherein at least aportion of the dirt collection chamber is constructed to permit a userto see the interior thereof. Alternately, or in addition, a filterhousing for a filter element, e.g., a physical filter element such as afoam filter) is provided wherein at least a portion of the filterhousing is transparent. The vacuum cleaner may have a plurality ofcyclonic stages wherein at least two cyclonic stages comprise aplurality of cyclones in parallel. In another aspect, this inventionrelates to improved cyclone designs. In a further aspect, this inventionrelates to improved designs for an array of cyclones, including designswherein the cyclones are positioned side by side, wherein some, andpreferably all of the cyclones are connected in parallel.

BACKGROUND OF THE INVENTION

Cyclonic vacuum cleaners are known in the art. In addition, cyclonicvacuum cleaners which comprise a first stage cyclone and plurality ofsecond stage cyclones are known. An example is shown in Conrad (U.S.Pat. No. 6,782,585). As shown therein, a vacuum cleaner has a firstcyclonic cleaning stage comprising a single first stage cyclone and asecond cyclonic cleaning stage downstream from the first cycloniccleaning stage and comprising a plurality of cyclones in parallel.

The plurality of second stage cyclones typically remove particulatematter finer than the particulate matter that is removed in the firstcyclonic cleaning stage. Accordingly, the coarsest particulate matterthat is entrained in an air stream is removed in the first cycloniccleaning stage and finer particulate matter is removed in the downstreamcyclonic cleaning stage. However, the air exiting the second cycloniccleaning stage may still contain sufficient particulate matter to damagea suction motor positioned downstream from the second cyclonic cleaningstage. Accordingly, as shown in Conrad, a filter may be positioneddownstream from the second cyclonic cleaning stage and upstream from thesuction motor.

SUMMARY OF THE INVENTION

In accordance with a first embodiment, a cyclone chamber for a vacuumcleaner may have a plate positioned intermediate the opposed ends (thetop end and the bottom end) of the casing of a cyclone separator so asto divide the interior of the cyclone casing into an upper cyclonechamber and a lower dirt collection area or chamber positioned beneaththe upper cyclone chamber. The plate, in conjunction with the structureof the cyclone separator, produces a passage that connects the cyclonechamber and the dirt collection chamber in communication such that dirtthat enters the cyclone chamber is conveyed to the dirt collectionchamber. All, or at least a portion of the passage, extends laterally oroutwardly.

The plate may be any of those known in the art such as those disclosedin U.S. Pat. No. 6,874,197. The plate may have a plurality of openingstherein or, preferably, it is solid. The plate is positioned inward fromthe outer wall of the casing so as to define an annular gap between theouter peripheral edge of the plate and the inner wall of the cyclonecasing. The plate overlaps a portion of a flow director or a portion ofan outwardly extending portion of the casing to define the passage. Theperipheral wall of the plate may be of varying geometries andorientations to assist in particle removal.

In an alternate embodiment, instead of a plate, the central portion ofthe bottom of the cyclone casing may be raised inwardly so as to definea plateau. Accordingly, the dirt collection chamber need not extendunder the plate or plateau.

In accordance with a first embodiment of this aspect, there is providedan indoor vacuum cleaner comprising:

-   -   (a) a dirty air inlet;    -   (b) a handle;    -   (c) a cyclone separator having an outer wall, a fluid inlet        downstream from the dirty air inlet and a fluid outlet;    -   (d) a plate having a cyclone chamber surface and positioned to        substantially divide the cyclone separator into a cyclone        chamber and a dirt collection chamber, each of the cyclone        chamber and the dirt collection chamber having an outer wall,        the outer wall of each of the cyclone chamber and the dirt        collection chamber having an outer perimeter, the dirt        collection chamber having a cyclone chamber end spaced from a        dirt collection floor;    -   (d) a passage extending between the cyclone chamber and the dirt        collection chamber, the passage configured such that separated        dirt travels at least outwardly as the dirt travels through the        passage; and,    -   (e) an air flow motor.

In one embodiment, the passage is formed between the cyclone chambersurface of the plate and an outwardly extending portion of the outerwall of the cyclone separator.

In another embodiment, the dirt collection chamber and the cyclonechamber each have an outer perimeter, the plate is positioned below theoutwardly extending portion and the outer perimeter of the dirtcollection chamber is larger then the outer perimeter of the cyclonechamber.

In another embodiment, the plate comprises a disc positioned adjacentthe cyclone chamber end of the dirt collection chamber and the dirtcollection chamber extends under at least a portion of the disc.

In another embodiment, the plate comprises a floor of the cyclonechamber and the dirt collection chamber does not extend under all of thefloor.

In another embodiment, the plate comprises a floor of the cyclonechamber and the dirt collection chamber does not extend under the floor.

In another embodiment, the vacuum cleaner further comprises a flowdirector having a flow directing surface that extends inwardly anddownwardly into the cyclone chamber from the outer wall of the cyclonechamber to a position above the plate and the passage is formed betweenthe flow director and the cyclone chamber surface of the plate.

In another embodiment, the vacuum cleaner further comprises an annulardirt collection region collinear with the cyclone chamber and separatedtherefrom by an inner annular wall that has a terminal end spaced fromthe plate and the passage is formed between the terminal end and thecyclone chamber surface of the plate.

In another embodiment, the fluid outlet comprises a tube having an inletand the tube extends along the axis of the cyclone chamber to a positionbelow the fluid inlet and has an end that is spaced from the plate.Preferably, a screen is provided in covering relation to the inlet ofthe air flow tube and the screen is spaced from the plate.

In another embodiment, the cyclone separator has a diameter adjacent thefluid inlet and the passage has a height that is less than ⅓ thediameter, preferably, less than ⅙ the diameter, more preferably lessthan 1/10 the diameter and most preferably less than 1/20 the diameter.

In another embodiment, the dirt collection chamber has a bottom that isopenable.

In another embodiment, the plate is removably subsequent to the bottombeing opened.

In accordance with a second embodiment of this aspect, there is provideda cyclone separator comprising:

-   -   (a) an outer wall, a fluid inlet and a fluid outlet, the fluid        outlet comprises a tube having an inlet and the tube extends        along the axis of the cyclone separator to a position below the        fluid inlet;    -   (b) a plate having a cyclone chamber surface and positioned to        substantially divide the cyclone separator into a cyclone        chamber and a dirt collection chamber, each of the cyclone        chamber and the dirt collection chamber having an outer wall,        the outer wall of each of the cyclone chamber and the dirt        collection chamber having an outer perimeter, the dirt        collection chamber having a cyclone chamber end spaced from a        dirt collection floor, the fluid outlet has an end that is        spaced from the plate; and,    -   (c) a passage extending between the cyclone chamber and the dirt        collection chamber, the passage configured such that separated        dirt travels at least outwardly as the dirt travels through the        passage.

In another embodiment, the plate is removably subsequent to the bottombeing opened.

It will be appreciated that any of the alternate embodiments set outwith respect to the first embodiment may be used with this secondembodiment. and that they may be combined in an apparatus in anycombination or sub-combination.

In accordance with a third embodiment of this aspect, there is provideda cyclone separator comprising:

-   -   (a) an outer wall, a fluid inlet and a fluid outlet, the cyclone        separator has a diameter adjacent the fluid inlet;    -   (b) a plate having a cyclone chamber surface and positioned to        substantially divide the cyclone separator into a cyclone        chamber and a dirt collection chamber, each of the cyclone        chamber and the dirt collection chamber having an outer wall,        the outer wall of each of the cyclone chamber and the dirt        collection chamber having an outer perimeter, the dirt        collection chamber having a cyclone chamber end spaced from a        dirt collection floor; and,    -   (c) a passage extending between the cyclone chamber and the dirt        collection chamber, the passage configured such that separated        dirt travels at least outwardly as the dirt travels through the        passage, the passage has a height that is less than ⅓ the        diameter.        It will be appreciated that any of the alternate embodiments set        out with respect to the first embodiment may be used with this        third embodiment and that they may be combined in an apparatus        in any combination or sub-combination.

In accordance with a second embodiment of the instant invention, a plateof the first embodiment, or any plate known in the art, is moveablymounted in a cyclone casing independent of the movement of a bottomopening door, or may be removably mounted. For example, the plate may besecured in position by means of magnets. Alternately, the plate may beheld in position mechanically, such as by the plate having one or moremembers that are received in an opening and secured therein by, e.g., areleasable snap fit. Thus the plate may be snapped into position andremoved therefrom as required. Alternately, or in addition, the platemay be mounted on a mechanical member for movement from a first positionwherein the plate divides the cyclone casing interior into a cyclonechamber and a dirt collection chamber and a second position wherein theplate has been moved to a position wherein the plate is positioned suchthat dirt may pass generally freely from one chamber to the other andthen out an open end of the cyclone casing. For example, the plate maybe pivoted to a position generally parallel to the longitudinal axis ofthe cyclone casing.

One advantage of this design is that the magnets permit the plate to beremoved for disposal and/or cleaning. In addition, a further advantageof using magnets is that the magnets will assist in attracting andretaining magnetic particles in the cyclone chamber, thereby increasingthe efficiency of the cyclone. In particular, carbon dust, which isproduced by electric motors that have brushes, is magnetic. Accordingly,the use of a cyclone or cyclones incorporating magnets will assist inthe removal of carbon dust from an air stream. Accordingly, it ispreferred to utilize a cyclone or array of cyclones containing magnetsdownstream from a motor and, optionally, in place of a filter, such as aHEPA filter. It will be appreciated that magnets may be used to assistin particle capture in any of the embodiments set out herein.

In accordance with a first embodiment of this aspect, there is provideda surface cleaning apparatus comprising:

-   -   (a) a dirt inlet;    -   (b) a handle;    -   (c) a cyclone separator having an outer wall, a fluid inlet        downstream from the dirt inlet and a fluid outlet;    -   a plate having a cyclone chamber surface and positioned to        substantially divide the cyclone separator into a cyclone        chamber and a dirt collection chamber, the plate being removably        mounted in the cyclone separator;    -   (d) a passage extending between the cyclone chamber and the dirt        collection chamber; and,    -   (e) a fluid flow motor.

In one embodiment, the plate is retained in position in the cycloneseparator by magnets.

In another embodiment, the plate is mechanically retained in position.For example, the cyclone separator has a mechanical engagement memberand the plate has a portion that is engageable with the mechanicalengagement member.

In another embodiment, the plate has a hand grip portion. Preferably,the hand grip portion comprises a shaft extending away from the plate.

In another embodiment, the dirt collection chamber extends under theplate.

In another embodiment, a flow director having a flow directing surfacethat extends inwardly and downwardly into the cyclone chamber from theouter wall of the cyclone chamber to a position above the plate.

In another embodiment, the surface cleaning apparatus is selected fromthe group consisting of a vacuum cleaner, a sweeper and a carpetextractor.

In another embodiment, the dirt collection chamber has a bottom that isopenable.

In another embodiment, the plate is removably subsequent to the bottombeing opened.

In accordance with a second embodiment of this aspect, there is provideda surface cleaning apparatus comprising:

-   -   (a) a dirt inlet;    -   (b) a handle;    -   (c) a cyclone separator having an outer wall, a fluid inlet        downstream from the dirt inlet, an openable bottom and a fluid        outlet;    -   (d) a plate having a cyclone chamber surface and positioned to        substantially divide the cyclone separator into a cyclone        chamber and a dirt collection chamber, the plate being movably        mounted in the cyclone separator independent of the bottom;    -   (e) a passage extending between the cyclone chamber and the dirt        collection chamber; and,    -   (f) a fluid flow motor.

It will be appreciated that any of the alternate embodiments set outwith respect to the first embodiment may be used with this secondembodiment. and that they may be combined in an apparatus in anycombination or sub-combination.

In accordance with a third aspect of the instant invention, a filtrationunit for a surface cleaning apparatus, preferably a vacuum cleaner, usesat least two cyclonic stages wherein each stage comprises a plurality ofcyclones in parallel. An advantage of this design is that thebackpressure across the cyclones is reduced. For example, the cyclonicseparation construction of the filtration unit, may include a firststage comprising a plurality of cyclones in parallel and a second stagecomprising a plurality of cyclones in parallel. In current known design,a single first stage cyclone is used. In comparison, pursuant to thisthird embodiment, the dirty air in a surface cleaning apparatus may befirst subjected to treatment in a cyclonic stage comprising a pluralityof cyclones in parallel and subsequently treated in a cyclonic stagecomprising a plurality of cyclones in parallel wherein both stages arepreferably upstream of the air flow motor. A third cyclonic stagecomprising a plurality of cyclones in parallel may be positioneddownstream from the air flow motor.

Preferably, each cyclone of one stage is not in fluid flow communicationwith all of the cyclones of the subsequent stage. More preferably, eachof the cyclones of one stage is in fluid communication with only onedownstream cyclone. Accordingly, the air exiting one cyclone is fed toonly one downstream cyclone.

In accordance with this preferred design, the outlet from an upstreamcyclone is connected in fluid communication with the inlet to adownstream cyclone. The outlet of the upstream cyclone may be tangentialor a spiral, which extends for less than a full revolution. Morepreferably, the outlet of the upstream cyclone and the inlet of thedownstream cyclone each are configured such that they individuallyextend for less than a full revolution. When the outlet and the inletare directly connected together, together they may comprise a continuousspiral that extends more than one revolution. Accordingly, the outletfrom the upstream cyclone and the inlet to the downstream cyclone, whenmerged, may form a continuous spiral. One advantage of this design isthat the rotational momentum of the air developed in an upstream cyclonemay be utilized and, preferably, enhanced in a downstream cyclone. Forexample, when an air stream enters a first cyclone, energy will beexpended to produce rotational motion in the air. If a tangential outletis utilized, then some of the rotational momentum may be preserved andin fact enhanced, as the air travels through the tangential outlet. Ifthe tangential outlet merges or is fed to the inlet of a downstreamcyclone, then the rotational momentum may be preserved and enhancedwithout having a substantially longer spiral or tangential inlet. Itwill be appreciated that the use of a tangential outlet from an upstreamcyclone and a tangential inlet to a downstream cyclone wherein they areconnected to maintain at least some rotational momentum, and preferablyare connected together, may be used in alternate constructions. Forexample, they may be used with any embodiment disclosed herein. They maybe used in embodiments wherein one cyclone is in communication with morethan one downstream cyclone and in other fields of application.

In accordance with a first embodiment of this aspect, there is provideda household appliance comprising:

-   -   (a) a dirt inlet;    -   (b) first and second cyclonic stages wherein each cyclonic stage        comprises a plurality of cyclones in parallel and the second        cyclonic stage is downstream from the first cyclonic stage; and,    -   (c) a fluid flow motor.

In one embodiment, at least one of the cyclones has a dirt collectionchamber that, during operation of the portable appliance, is not incommunication with any other cyclone.

In another embodiment, each cyclone of at least one of the cyclonicstages has an associated dirt collection chamber and each dirtcollection chamber is associated with only one cyclone. Preferably, allof the dirt collection chambers are emptied concurrently. Morepreferably, the dirt collection chambers have a common openable bottom.

In another embodiment, each cyclone in the second cyclonic stage isconnected in fluid flow communication with one cyclone in the firstcyclonic stage.

In another embodiment, each cyclone of the first cyclonic stage has afluid outlet and each cyclone of the second cyclonic stage has a fluidinlet and the outlet of a cyclone of the first cyclonic stage and theinlet of a cyclone of the second cyclonic stage form a continuouspassage. Preferably, the fluid outlet is configured to maintain at leastsome of the cyclonic flow produced by fluid flowing through anassociated cyclone. More preferably, the passage comprises a continuouscurve.

In another embodiment, at least one of the cyclonic stages comprises atleast 15 cyclones in parallel, preferably at least 20 and morepreferably about 25 or more.

In another embodiment, at least one of the cyclonic stages comprises atleast one cyclone per square inch and, preferably, at least two cyclonesper square inch.

In another embodiment, the appliance is a surface cleaning apparatus, ahousehold air cleaner or a breathing mask.

In another embodiment, the appliance is a surface cleaning apparatus.

In another embodiment, the surface cleaning apparatus is selected fromthe group consisting of a vacuum cleaner, a sweeper and a carpetextractor.

In another embodiment, the cyclonic stages are positioned upstream fromthe motor. Preferably, the air travels from the cyclonic stages to themotor without passing through a filter.

In another embodiment, the portable appliance further comprises anadditional cyclonic stage wherein three cyclonic stages are positionedupstream from the motor.

In another embodiment, the air travels from the three cyclonic stages tothe motor without passing through a filter.

In another embodiment, the portable appliance further comprises a postmotor cyclonic stage. Preferably, fluid exiting the post motor cyclonicstage has a level of filtration at least equal to HEPA without the useof a HEPA filter. Alternately, or in addition, the post motor cyclonicstage comprises a plurality of cyclones in parallel.

In another embodiment, the first and second cyclonic stages are eachseparately removable from the appliance.

It will be appreciated that any of these alternate embodiments may becombined in an apparatus in any combination or sub-combination.

In accordance with a fourth aspect of the instant invention, a surfacecleaning apparatus, preferably a vacuum cleaner, has two cyclonic stageswherein one of the cyclonic stages comprises a plurality of cyclones inparallel and at least one dirt collection chamber associated therewith,wherein the plurality of cyclones and associated dirt collection chamberor chambers comprise a cyclonic unit which is removable from the surfacecleaning apparatus as a sealed unit, other than openings for fluid flowpassages leading to and from the cyclones. In a preferred embodiment,the dirt collection chambers have a sufficient capacity such that theymay require emptying only once a month, during normal use, preferablyonce every three months and more preferably once every four months. Onceadvantage of this design is that, due to the increased storage capacity,the cyclonic unit need only be removed and emptied occasionally andtherefore may remain in the surface cleaning apparatus much of the timewhen a main or first stage collection chamber is removed for emptying.For example, if a first cyclonic stage is removed for emptying,retaining a second cyclonic stage in the surface cleaning apparatusreduces the weight and size of the component that is removed from thesurface cleaning apparatus when the first stage is to be emptied.

Alternately, or in addition, in accordance with this fourth embodiment,a surface cleaning apparatus, preferably a vacuum cleaner, has at leastfirst and second cleaning stages wherein the first cleaning stage has adirt collection member and the second cleaning stage comprises aplurality of cyclones and at least one dirt collection chamber, whereinthe first and second cleaning stages are emptied separately. Preferably,each stage comprises a plurality of cyclones and, more preferably, eachstage comprises a plurality of dirt collection chambers.

In accordance with a first embodiment of this aspect, there is provideda portable vacuum cleaner comprising:

-   -   (a) a dirty air inlet;    -   (b) a handle;    -   (c) at least first and second cleaning stages wherein the first        cleaning stage has a dirt collection member and the second        cleaning stage comprises a plurality of cyclones and at least        one dirt collection chamber, wherein the first and second        cleaning stages are emptied separately; and,    -   (d) an air flow motor.

In one embodiment, the second cleaning stage is removed from the firstcleaning stage prior to emptying the second cleaning stage.

In another embodiment, the second cleaning stage is removed by itselffrom the vacuum cleaner. Preferably, second cleaning stage includes atleast one filter.

In another embodiment, the first and second cleaning stages are eachseparately removable from the vacuum cleaner. Preferably, the secondcleaning stage is downstream from the first cleaning stage. Alternately,or in addition, the first cleaning stage comprises at least one cycloneand the dirt collection member comprises a dirt collection chamber.

In another embodiment, the first cleaning stage has a capacity to storedirt for a predetermined number of one hour sessions of use of thevacuum cleaner for regular household cleaning and the second cleaningstage has a capacity to store dirt for at least three times and,preferably ten times, the predetermined number.

In another embodiment, each of the first and second cleaning stages hasa storage volume and the storage volume of the second stage is selectedsuch that, when the vacuum cleaner is used to collect particulate matterfor which the vacuum cleaner is designed, the second cleaning stagerequires emptying not more than once for every three times, andpreferably not more than once every ten times, the first stage isemptied.

In another embodiment, the second cleaning stage has a capacity to storedirt for at least one month of regular use of the vacuum cleaner.

In another embodiment, the second cleaning stage has a capacity to storedirt for at least three months of regular use of the vacuum cleaner.

In another embodiment, the second cleaning stage has a plurality of dirtcollection chambers that are emptied concurrently.

In another embodiment, each cyclone of the second cleaning stage has anassociated dirt collection chamber and each dirt collection chamber isassociated with only one cyclone and all of the dirt collection chambersof the second cleaning stage are emptied concurrently.

In another embodiment, the plurality of cyclones and at least one dirtcollection chamber are removable as a closed unit from the vacuumcleaner. Preferably, the dirt collection chamber has an openable bottom.Alternately, or in addition, the second cleaning stage has a pluralityof dirt collection chambers that are emptied concurrently.

In another embodiment, the second cleaning stage is sealed when removedfrom the vacuum cleaner other than fluid flow passages leading to andfrom the cyclones.

In another embodiment, the vacuum cleaner is selected from the groupconsisting of an upright vacuum cleaner, a wet/dry vacuum cleaner and acanister vacuum cleaner.

In another embodiment, the vacuum cleaner further comprises a doormoveable to an open position wherein the second cleaning stage isremovable when the door is in the open position.

In another embodiment, the second cleaning stage is slidably removablefrom the vacuum cleaner.

In another embodiment, the second cleaning stage is removably mounted tothe first cleaning stage. Preferably, the second cleaning stage ismoveable upwardly from the first cleaning stage.

It will be appreciated that any of these alternate embodiments may becombined in an apparatus in any combination or sub-combination.

In accordance with a second embodiment of this aspect, there is provideda surface cleaning apparatus comprising:

-   -   (a) a dirt inlet;    -   (b) a handle;    -   (c) at least first and second cleaning stages wherein the second        cleaning stage comprises a plurality of cyclones and at least        one dirt collection chamber, wherein, other than fluid flow        passages leading to and from the cyclones, the second cleaning        stage is removable from the surface cleaning apparatus as a        sealed unit for emptying; and,    -   (d) an air flow motor.

It will be appreciated that any of the alternate embodiments set outwith respect to the first embodiment may be used with this secondembodiment. and that they may be combined in an apparatus in anycombination or sub-combination

In accordance with a fifth aspect of this invention, a surface cleaningapparatus is constructed with a plurality of cyclones in parallel thathave at least one associated dirt collection chamber, and preferably aplurality of dirt collection chambers, wherein the interior of the atleast one dirt collection chamber, and preferably each dirt collectionchamber, is visible from a position exterior to the surface cleaningapparatus. Therefore, a consumer can see the amount of dirt collected inthe dirt chamber and determine when the dirt chamber should be emptied.This is particularly advantageous if the surface cleaning apparatus hastwo cyclonic stages and the stages are separately emptyable and, morepreferably, separately removable. Therefore, a consumer will be able tovisually determine when the stage should be emptied. This aspect isparticularly preferred if combined with the fourth aspect, especially ifthe second stage has a dirt capacity wherein it need not be emptiedevery time the first stage is emptied.

While all or part of the associated cyclone(s) and the dirt collectionchamber(s) may be transparent (i.e., see through), in a particularlypreferred embodiment, the only transparent portion need be the upper endof the dirt collection chamber (e.g., the portion extending below amaximum fill line). Thus only the top, or all of, the dirt collectionchamber(s) may be transparent. One advantage of this design is that whenthe dirt collection bin is full, a user will not see into the interiorof any of the dirt collection chamber and will have a visual signal toempty the cyclonic stage. If both the interior of the cyclone and thedirt collection chamber are visible, then a consumer may overfill thedirt collection chamber thereby decreasing the efficiency of the surfacecleaning apparatus. Preferably, the portion above a predetermined fillline is not transparent. For example, all of the cyclone casing may bemade from transparent plastic and the required portion may be masked bycoating it (e.g., paint) and/or by applying a label.

In accordance with a first embodiment of this aspect, there is provideda surface cleaning apparatus comprising:

-   -   (a) a dirt inlet;    -   (b) a handle;    -   (c) a cyclonic cleaning unit comprising a plurality of cyclones        and at least one dirt collection chamber, each of the plurality        of cyclones having an outer wall, an interior, a fluid inlet        downstream from the dirt inlet and a fluid outlet;    -   (d) the at least one dirt collection chamber having an outer        wall and an interior, wherein the surface cleaning apparatus is        constructed such that the interior of the at least one dirt        collection chamber is visible from a position exterior to the        surface cleaning apparatus; and,    -   (e) a fluid flow motor.

In one embodiment, the outer wall of the at least one dirt collectionchamber has at least a transparent portion.

In another embodiment, the at least one dirt collection chamber has amaximum recommended dirt capacity and the transparent portion extendsdownwardly from a position defining the maximum recommended dirtcapacity.

In another embodiment, the at least one dirt collection chamber has amaximum recommended dirt capacity and the outer wall of the at least onedirt collection chamber is opaque above a position defining the maximumrecommended dirt capacity.

In another embodiment, the outer wall of the at least one dirtcollection chamber is an outer wall of the surface cleaning apparatus.Preferably, all of the outer wall of the at least one dirt collectionchamber is transparent. More preferably, the surface cleaning apparatusfurther comprises a transparent wall positioned radially outwardly ofthe outer wall of the at least one dirt collection chamber.

In another embodiment, the surface cleaning apparatus further comprisesa wall positioned exterior to the outer wall of the at least one dirtcollection chamber, at least a sufficient portion of which istransparent to permit a user to view the transparent portion of theouter wall of the at least one dirt collection chamber.

In another embodiment, each of the plurality of cyclones has anassociated dirt collection chamber. Preferably each of the associateddirt collection chambers has an outer wall, at least a portion of whichis transparent. Alternately, or in addition, each of the associated dirtcollection chambers has a bottom that is openable.

In another embodiment, each of the plurality of cyclones has a platepositioned to substantially divide the cyclone separator into a cyclonechamber and a dirt collection chamber.

In another embodiment, the surface cleaning apparatus has at least firstand second cyclonic stages and the cyclonic cleaning unit comprises thesecond cyclonic stage.

In another embodiment, the first and second cyclonic stages are eachseparately removable from the surface cleaning apparatus.

In another embodiment, the first cyclonic stage comprises a singlecyclone.

In another embodiment, the first cyclonic stage comprises a plurality ofcyclones in parallel. Preferably, the plurality of cyclones of the firstcyclonic cleaning unit have at least one first stage dirt collectionchamber, the at least one first stage dirt collection chamber having afirst stage outer wall and a first stage interior, wherein the surfacecleaning apparatus is constructed such that the first stage interior isvisible from a position exterior to the surface cleaning apparatus.

In another embodiment, at least a portion of the outer wall of each ofthe cyclones is transparent.

In another embodiment, the outer wall of each of the cyclones istransparent.

In another embodiment, the portion of the outer walls of the cyclonesform an outer wall of the surface cleaning apparatus.

In another embodiment, the surface cleaning apparatus further comprisesa wall positioned exterior to the outer wall of the cyclones, at least asufficient portion of which is transparent to permit a user to view thetransparent portion of the outer wall of the cyclones.

In another embodiment, each cyclone and associated dirt collectionchamber is integrally molded from transparent plastic. Preferably, theouter walls of the dirt collection chambers are a portion of an outersurface of the surface cleaning apparatus and the transparent plastic ofthe cyclone is treated to render the sidewalls of the cyclones opaque.Alternately, or in addition, the surface cleaning apparatus furthercomprises a wall positioned exterior to the cyclonic cleaning unit, atleast a sufficient portion of which is transparent to permit a user toview the interior of only the dirt collection chambers.

In another embodiment, the surface cleaning apparatus further comprisesa header in fluid flow communication with the fluid outlets from thecyclones wherein the header is transparent.

In another embodiment, the surface cleaning apparatus further comprisesa filter housing, at least a portion of which is transparent.Preferably, the transparent portion of the filter housing is visiblewhen the vacuum cleaner is in use.

In another embodiment, the surface cleaning apparatus further comprisesa filter housing, at least a portion of which is transparent wherein thetransparent portion of the filter housing is visible when at least oneof the cyclonic stages is removed.

It will be appreciated that any of these alternate embodiments may becombined in an apparatus in any combination or sub-combination.

In accordance with a second embodiment of this aspect, there is provideda surface cleaning apparatus comprising:

-   -   (a) a dirt inlet;    -   (b) a handle;    -   (c) at least one cyclonic cleaning stage;    -   (d) a filter housing, at least a portion of which is        transparent; and,    -   (e) a fluid flow motor.

In one embodiment, the transparent portion of the filter housing isvisible when the vacuum cleaner is in use.

In another embodiment, the cyclonic cleaning stage is removable from thesurface cleaning apparatus and the transparent portion of the filterhousing is visible when the cyclonic cleaning stage is removed.

In another embodiment, the surface cleaning apparatus further comprisesan openable door and the transparent portion of the filter housing isvisible when the door is open.

In another embodiment, filter is a pre-motor filter.

In another embodiment, all of the filter housing is transparent.

In another embodiment, the surface cleaning apparatus has at least firstand second cyclonic cleaning stages. Preferably, the first and secondcyclonic cleaning stages are each separately removable from the surfacecleaning apparatus. Alternately, or in addition, the first cycloniccleaning stage comprises a single cyclone. Alternately, or in addition,at least one cyclonic cleaning stage comprises a plurality of cyclonesin parallel.

It will be appreciated that any of the alternate embodiments set outwith respect to the first embodiment may be used with this secondembodiment and that they may be combined in an apparatus in anycombination or sub-combination.

In accordance with a sixth aspect of this invention, a surface cleaningapparatus is provided with at least a visible portion of the interior ofa cyclone separator and an illumination member that is positioned toprovide illumination to at least a portion of the cyclone separatorinterior. One advantage of this design is that it enhances the abilityof a user to view the cyclonic action in the cyclone chamber (and knowif there is a problem by the air flow pattern) and/or to know when thedirt collection chamber requires emptying. For example, if a vacuumcleaner is used under low light conditions, e.g. at night in a room,then it may be difficult for a consumer to view the interior of thecyclone separator. It will be appreciated that this aspect isparticularly useful if combined with one or both of the fourth and fifthaspects.

If too much dirt accumulates in a dirt collection chamber, then theefficiency of the cyclone decreases and the amount of dirt that travelsthrough the cyclone without being captured increases. This may result inexcessive dirt passing through the suction motor of an appliance, suchas a vacuum cleaner, thereby shortening the life expectancy of theappliance. Enhancing the ability of a consumer to monitor the dirt thathas been captured by a cyclone separator reduces the likelihood of aconsumer allowing too much dirt to accumulate in a dirt collection binof a cyclone.

In accordance with this aspect, all or a portion of the cycloneseparator casing may be constructed from an electroluminescent material.Alternately, the inner wall of all or a portion of a cyclone may becoated with an electroluminescent material.

For example, all or a portion of the front portion of the cyclone may betransparent and all or a portion of the rear portion may have anelectroluminescent coating. The illumination provided by theelectroluminescent material enhances the ability of a consumer to viewthe interior of the cyclone chamber and determine the amount of dirtthat has accumulated therein. Accordingly, it will be more apparent to aconsumer when the dirt collection chamber or bin (which is preferablypart of the cyclone separator casing) needs to be emptied. Alternately,only the cyclone separator casing housing the cyclone chamber may be sotreated or made of an electroluminescent material, whereby theappearance of dirt accumulating in the cyclone chamber may be a visiblesignal to a user to empty the dirt collection chamber.

Alternately, or in addition, one or more lights may be provided internalof a cyclone chamber and/or directed at the interior of a cyclonechamber so as to enhance the ability of a consumer to determine theamount of dirt present in the cyclone chamber. Preferably, the lightcomprises one or more LEDs.

In accordance with an embodiment of this aspect, there is provided asurface cleaning apparatus having an outer surface and comprising:

-   -   (a) a dirt inlet;    -   (b) a handle;    -   (c) a cyclone separator having a cyclone separator interior and        an outer wall having an inner surface, the cyclone separator        comprising a cyclone chamber and a dirt collection chamber, the        dirt collection chamber and the cyclone chamber each having an        outer wall, the surface cleaning apparatus is constructed such        that the cyclone separator interior is visible from a position        exterior to the surface cleaning apparatus;    -   (d) an illumination member positioned to provide illumination to        at least a portion of the cyclone separator interior; and,    -   (e) a fluid flow motor.

In one embodiment, the illumination member comprises electroluminescentmaterial and a portion of the cyclone separator is constructed from theelectroluminescent material. Preferably, the cyclone separator has afront portion and a rear portion and the rear portion is constructedfrom the electroluminescent material and the front portion istransparent.

In another embodiment, the illumination member comprises anelectroluminescent coating and a portion of the cyclone separator iscoated with the electroluminescent coating. Preferably, the cycloneseparator has a front portion and a rear portion and the rear portion iscoated with the electroluminescent coating and the front portion istransparent.

In another embodiment, the illumination member comprises at least onelight.

In another embodiment, the light is positioned within the cycloneseparator.

In another embodiment, the light is positioned exterior to the cycloneseparator and light produced thereby is directed inwardly to the cycloneseparator interior.

In another embodiment, the light comprises at least one LED.

In another embodiment, the dirt collection chamber has a dirt chamberinterior, wherein the surface cleaning apparatus is constructed suchthat the interior of the dirt collection chamber is visible from aposition exterior to the surface cleaning apparatus and the illuminationmember is positioned to provide illumination to at least a portion ofthe dirt chamber interior.

In another embodiment, the outer wall of the cyclone separator has atleast a transparent portion and the transparent portion forms a portionof the outer surface of the surface cleaning apparatus.

In another embodiment, the outer wall of the dirt collection chamber hasat least a transparent portion and the transparent portion forms aportion of the outer surface of the surface cleaning apparatus.

In another embodiment, the outer wall of the cyclone separator has atleast a transparent portion and the surface cleaning apparatus furthercomprises a wall positioned exterior to the outer wall of the cycloneseparator, at least a sufficient portion of which is transparent topermit a user to view the transparent portion of the outer wall of thecyclone separator.

In another embodiment, the outer wall of the dirt collection chamber hasat least a transparent portion and the surface cleaning apparatusfurther comprises a wall positioned exterior to the outer wall of thedirt collection chamber, at least a sufficient portion of which istransparent to permit a user to view the transparent portion of theouter wall of the dirt collection chamber.

In another embodiment, all of the outer wall of the dirt collectionchamber is transparent. Preferably, the surface cleaning apparatusfurther comprises a transparent wall positioned radially outwardly ofthe outer wall of the dirt collection chamber. Alternately, or inaddition, all of the outer wall of the cyclone separator is transparentand at least one of the transparent plastic of the cyclone separator andthe transparent wall is treated to inhibit a user viewing the cyclonechamber.

In another embodiment, all of the outer wall of the cyclone separator istransparent plastic, the outer wall of the cyclone separator is aportion of the outer surface of the surface cleaning apparatus and thetransparent plastic of the cyclone separator is treated to render theouter wall of the cyclone chamber opaque.

It will be appreciated that any of these alternate embodiments may becombined in an apparatus in any combination or sub-combination.

In accordance with a seventh aspect of this invention, a surfacecleaning apparatus is provided with a cyclonic stage comprising aplurality of cyclones in parallel and a plurality of dirt collectionchambers that are emptied concurrently wherein the plurality of cyclonesand the plurality of dirt collection chambers are removable as a unitfrom the surface cleaning apparatus. One advantage of this design isthat by using a plurality of dirt collection chambers, cross flowbetween cyclones via the dirt exit of the cyclones is reduced. In aparticularly preferred embodiment, each cyclone has its own dirtcollection chamber. In practice, there may be a different vacuum levelin each cyclone of a plurality of cyclones. If there is a common dirtcollection chamber for a plurality of cyclones, then some air will tendto travel out the dirt exit of one cyclone and across the common dirtcollection chamber and enter a second cyclone via the dirt exit of thesecond cyclone, resulting in some dirt reentering the second cyclone. Afurther advantage is that the cyclone dirt chambers are removed from thesurface cleaning apparatus while closed so that they may be transportedto a garbage can or the like for emptying without the contents beingscattered during transport.

In accordance with an embodiment of this aspect, there is provided asurface cleaning apparatus comprising:

-   -   (a) a dirt inlet;    -   (b) a handle;    -   (c) at least a first cleaning stage comprising a plurality of        cyclones in parallel and a plurality of dirt collection chambers        that are emptied concurrently wherein the plurality of cyclones        and the plurality of dirt collection chambers are removable as a        unit from the surface cleaning apparatus; and,    -   (d) an air flow motor.

In one embodiment, each cyclone has an associated dirt collectionchamber and each dirt collection chamber is associated with only onecyclone and all of the dirt collection chambers are emptiedconcurrently. Preferably, the dirt collection chambers have a commonbottom that is openable.

In another embodiment, the surface cleaning apparatus further comprisesa second cleaning stage and the first cleaning stage is removed from thesecond cleaning stage prior to emptying the plurality of dirt collectionchambers.

In another embodiment, the surface cleaning apparatus further comprisesa second cleaning stage and the first cleaning stage is removed byitself from the surface cleaning apparatus. Preferably, the first andsecond cleaning stages are concurrently removed from the surfacecleaning apparatus and the first cleaning stage is removed from thesecond cleaning stage prior to emptying the plurality of dirt collectionchambers.

In another embodiment, first cleaning stage comprises a cycloniccleaning unit that is sealed when removed from the surface cleaningapparatus other than fluid flow passages leading to and from thecyclones.

In another embodiment, the first cleaning stage includes at least onefilter removable with the first cleaning stage.

In another embodiment, the surface cleaning apparatus further comprisesa door moveable to an open position wherein the first cleaning stage isremovable when the door is in the open position.

In another embodiment, the first cleaning stage is slidably removablefrom the surface cleaning apparatus.

In another embodiment, the cyclonic cleaning unit is removably mountedto a second cleaning stage and the first cleaning stage is moveableupwardly from the first cleaning stage.

In another embodiment, the first cleaning stage comprises at least 15cyclones in parallel.

In another embodiment, the first cleaning stage comprises at least onecyclone per square inch, preferably at least two cyclones per squareinch, and more preferably at least four cyclones per square inch.

In another embodiment, the surface cleaning apparatus is selected fromthe group consisting of a vacuum cleaner, a sweeper and a carpetextractor.

In another embodiment, cyclones of the first cleaning stage are spacedapart to define a region between adjacent cyclones in which particulatematter collects. Preferably the region has a floor that is moveable,whereby the collection area may be emptied when the floor is moved.Preferably, the dirt collection chambers of the first cleaning stagehave a common bottom that is openable and the floor is moved when thecommon bottom is opened. Preferably the common bottom and the floorcomprise a continuous member that is moveably mounted, and preferablypivotally mounted, to the first cleaning stage.

In another embodiment, the surface cleaning apparatus further comprisesa second cleaning stage and the first cleaning stage is positionedexterior to the second cleaning stage.

In another embodiment, the surface cleaning apparatus further comprisesa second cleaning stage comprising at least one cyclone and theplurality of cyclones are positioned exterior to the at least onecyclone.

In another embodiment, the surface cleaning apparatus further comprisesa second cleaning stage comprising at least one cyclone and the firstcleaning stage is positioned exterior to the at least one cyclone.

It will be appreciated that any of these alternate embodiments may becombined in an apparatus in any combination or sub-combination.

In accordance with an eighth aspect of the instant invention, a cyclonechamber is provided with a screen that covers all or a portion of theoutlet from the cyclone chamber and which is removable and, optionally,replaceable, preferably through the top (air entrance end) of thecyclone chamber. In a preferred embodiment, the screen is formed with ahandle (e.g., the air outlet conduit) so that a consumer need not touchthe screen during removal. A part of the top panel of the cyclone casingmay be removable with the screen as an assembly and may be used tosecure the assembly in position (e.g., by a screw thread, bayonet mountor other releasable means that engages with the portion of the cycloneseparator casing that is not removed with the screen). The screen mayhave longitudinally extending side walls to define an outer perimeterscreen and a transversely extending wall to define a central screen,which are connected together so as to define a screen member that has anopen volume (a capture region) that is surrounded on its length, widthand height by a screen material. For example, the screen may be Hshaped, a square U shape or a square inverted U shape.

Alternately, or in addition, in accordance this aspect, the screen isprovided in a cyclone chamber such that the air travels into an openenclosure of the screen prior to traveling through the screen to theoutlet from the cyclone chamber. For example, the screen may be H shapedor a square inverted U shape. The open enclosure is surrounded on allsides (other than the bottom), by screen material, thereby enlarging thesurface area of screen through which the air may travel prior toentering the cyclone outlet. The air will initially tend to travelupwardly into the open enclosure, and through the transverse member tothe cyclone outlet. If the transverse member becomes clogged, the airmay pass through the side wall of the open enclosure and then travelback inwardly through additional screen material into the interior ofthe screen prior to exiting through the cyclone outlet.

The screen is preferably constructed from a material that will assist inretaining or trapping particulate matter. For example, the screen may bemade from an adhesive material. Alternately, or in addition, the screenmay be provided with microfilaments that extend outwardly therefrom. Themicrofilaments create a surface (for example like a very fine Velcro™)material on which elongate material such as hair may become trapped.

In accordance with a first embodiment of this aspect, there is provideda surface cleaning apparatus comprising:

-   -   (a) a dirt inlet;    -   (b) a handle;    -   (c) a cyclone separator having an outer wall, a top, a fluid        inlet downstream from the dirty inlet and a fluid outlet;    -   (d) a screen positioned around the fluid outlet such that fluid        exiting the cyclone separator passes through the screen and the        screen is removable through the top of the cyclone separator;        and,    -   (e) a fluid flow motor.

In one embodiment, the fluid outlet has an upper portion positionedabove the top of the cyclone separator and is removable with the screen.

In another embodiment, the upper portion of the fluid outlet is a handlefor the screen.

In another embodiment, a fluid flow conduit is collinear with the fluidoutlet, extends through the cyclone chamber and has an upper portionpositioned above the top of the cyclone separator and the upper portionof the fluid outlet is a handle for the screen.

In another embodiment, the screen is rotatably mounted to the cycloneseparator.

In another embodiment, the screen has a larger diameter than the fluidoutlet. Preferably, the top of the cyclone chamber has a removableannular band that has a diameter larger than the diameter of the screen.More preferably, the removable annular band is removable with the fluidconduit and may form a one piece assembly with the fluid conduit (e.g.,they may be integrally molded).

In another embodiment, the screen has an outer perimeter defining acavity and a transverse member extending across the cavity.

In another embodiment, the fluid outlet has an inlet and the screen hasa longitudinal surface that is parallel to the fluid outlet, extendspast the inlet of the fluid outlet, and first and second opposed endsand the transverse member is positioned between the first and secondopposed ends and the inlet to the fluid outlet is surrounded by thelongitudinal surface and the transverse member. The transverse membermay be positioned mid way along the longitudinal surface. Alternatelythe first opposed end is positioned towards the top and the transversemember is positioned adjacent the first opposed end. Alternately, thesecond opposed end is positioned distal from the top and the transversemember is positioned adjacent the second opposed end.

It will be appreciated that any of these alternate embodiments may becombined in an apparatus in any combination or sub-combination.

In accordance with a second embodiment of this aspect, there is alsoprovided a surface cleaning apparatus comprising:

-   -   (a) a dirt inlet;    -   (b) a handle;    -   (c) a cyclone separator having an outer wall, a top, a fluid        inlet downstream from the dirty inlet and a fluid outlet, the        fluid outlet having an inlet;    -   (d) a screen positioned around the inlet of the fluid outlet,        the screen having a longitudinal surface that is parallel to the        fluid outlet, extends past the inlet of the fluid outlet, first        and second opposed ends and a transverse member positioned to        define a cavity interior of the longitudinal surface that is        open to the fluid in the cyclone separator without passing        through the screen; and,    -   (e) a fluid flow motor.

It will be appreciated that any of the alternate embodiments set outwith respect to the first embodiment may be used with this secondembodiment and that they may be combined in an apparatus in anycombination or sub-combination.

It will be appreciated that any one of these aspects may be combinedwith one or more of the other aspects in any combination orsub-combination.

In accordance with another aspect of this invention, there is providedan improved cyclone, which may be used in a vacuum cleaner. Inparticular, a cyclone may have an inlet that is positioned exterior tothe cyclone chamber. For example, it may be positioned on top of thecyclone. It may be formed as the upper portion of the cyclone chambercasing or it may be mounted on top of the upper casing of the cycloneand be in air flow communication with the cyclone chamber formed in thecasing. The inlet comprises a spiral or tangential inlet. Preferably,the spiral ramp may extend through an arc from 15 to 360° and,preferably from 25 to 270° and, more preferably from 25 to 90°. It willbe appreciated that in an alternate embodiment, the spiral inlet thatextends for less than a full revolution may be constructed in the sidewall of a cyclone bin. This construction may be used in conjunction withany of the aspects set out herein or, alternately, on its own.

In accordance with another aspect of the instant invention, a cyclone ora plurality of cyclones may be made from a biodegradable material. Anadvantage of this design is that the cyclones may be disposable.Accordingly, when deposited in a land fill site, the cyclone casing willeventually biodegrade. For example, a cyclone may be made of a paperbased material that is compression molded or an injection molded starchor glucose based material so that the product is biodegradable. Thisconstruction may be used in conjunction with any of the aspects set outherein or, alternately, on its own.

In accordance with another aspect of the instant invention, the casingof a cyclone chamber, or a portion thereof, may be made from adeformable material, such as an elastomeric material. Preferably, thecasing has sufficient rigidity to maintain its shape during storage andtransportation of a vacuum cleaner and, more preferably, during normaloperation of a vacuum cleaner. This construction may be used inconjunction with any of the aspects set out herein or, alternately, onits own.

In accordance with another aspect of the instant invention, the innersurface of the outer wall of a cyclone separator, or a portion thereof,and/or the inlet and outlet and any components therein may be coatedwith an adhesive material or may be lined with a removable adhesivematerial. For example, the adhesive material may be agar or pectin or arubber based adhesive. One advantage of this embodiment is thatparticulate matter will adhere to the adhesive material as the airrotates in the cyclone chamber and contacts the outer wall of thecyclone casing or other portion having adhesive material associatedtherewith. Accordingly, the efficiency of the cyclone will be increasedby dirt adhering to the outer wall of the cyclone. In accordance withthis aspect of the invention, the cyclone, or an adhesive liner insertedin the cyclone, may be disposable. Accordingly, the cyclone casing maybe constructed from a thin walled plastic (e.g. a vacuum moldedplastic). Alternately, the adhesive that is selected may release dirt oncontact with water. Accordingly, if a user washes out the interior ofthe cyclone, then the dirt, which has adhered to the outer wall of thecyclone chamber, will be removed. In a particularly preferredembodiment, it is preferred that the adhesive be provided on adownstream cyclone which is designed to remove finer particulate mater.Accordingly, this embodiment is particularly preferred for use in thesecond, third, fourth or other sequential stage(s) of a multistagecyclone separator where small quantities of fine particles are to becollected. This construction may be used in conjunction with any of theaspects set out herein or, alternately, on its own.

In accordance with another aspect of the instant invention, the cyclonecasing may be constructed from, or may be coated with, a biocidalmaterial. The biocidal material will prevent the growth ofmicrobiologics, or reduce the tendency of microbiologics to grow, in thecyclone chamber. For example, a biocidal agent such as a tin arseniccompound may be added to the plastics of which the cyclone bins aremolded, or biocidal materials such as surfactant lipid preparations maybe applied to the interior and/or exterior surfaces of the cyclones toinhibit the growth of bacteria, molds, or viruses. This construction maybe used in conjunction with any of the aspects set out herein or,alternately, on its own.

In accordance with another aspect of the instant invention, all or aportion of a cyclone casing, which may include the inlet and/or outletsof the cyclone casing and any screen material utilized therein, may bemanufactured from or coated with an electret material. Electretmaterials are constructed so as to have a permanent electric chargepolarization. For example, a plastic may be heated in the presence of anelectric field and allowed to cool, resulting in permanent polarizationof the plastic. One advantage of this embodiment is that all or aportion of the cyclone casing may be constructed to function as a magnetthereby increasing the efficiency of a cyclone by removing electricallycharged particles. Typically, particulate matter that travels through acyclone becomes charged due to the passage of the material at high speedthrough the cyclone separator. Accordingly, the use of a cyclone casingor portions thereof, which are made from materials that have a permanentelectrostatic field, enhances the separation efficiency of the cyclone,particularly finer particulate matter, by combining electrostaticattraction and cyclonic separation. Accordingly, this embodiment isparticularly preferred for use in the second, third, fourth or othersequential stage(s) of a multistage cyclone separator where smallquantities of fine particles are to be collected. This construction maybe used in conjunction with any of the aspects set out herein or,alternately, on its own.

In accordance with another aspect of the instant invention, some or allof the particle collected in one cyclone are conveyed to anothercyclone, which may be upstream or downstream, whereby at least some ofthe particulate matter conveyed to the upstream or downstream cyclone iscollected in the particle collector for the upstream or downstreamcyclone. One advantage of this embodiment is that a consumer may need toonly empty a single cyclone bin of a surface cleaning apparatus. Thisconstruction may be used in conjunction with any of the aspects set outherein or, alternately, on its own.

In accordance with another aspect of the instant invention an array ofcyclones is provided wherein the cyclones may be sized such that thereare at least 2 cyclones, preferably at least 5 cyclones, more preferablyat least 10 cyclones and most preferably at least 25 cyclones per squareinch measured in a plane transverse to the longitudinal axis of thecyclone separators. This construction may be used in conjunction withany of the aspects set out herein or, alternately, on its own.

In any aspect of this invention, a cyclone separator may include anyplate known in the art for defining a dirt collection chamber in acyclone separator below the cyclone chamber. The plate is preferablypositioned inward from the outer wall of the cyclone separator casing soas to define an annular gap between the outer peripheral edge of theplate and the inner wall of the cyclone casing. If the plate is spacedfrom the inner wall of the cyclone separator casing, then the plate hasan upper surface and a lower surface and a peripheral wall that extendsbetween the upper and lower surfaces. The peripheral wall may be ofvarying geometries and orientations to assist in particle removal.

BRIEF DESCRIPTION OF THE DRAWINGS

These and other advantages of the instant invention will be more fullyand completely understood in association with the following descriptionof preferred embodiments of this invention wherein:

FIG. 1 is a perspective view of a preferred embodiment of a vacuumcleaner incorporating two cyclonic cleaning stages;

FIG. 2 is a cross section along line 2-2 of the vacuum cleaner of FIG.1;

FIG. 2 a is an exploded view of the cyclonic cleaning stages of thevacuum cleaner of FIG. 1;

FIGS. 3, 3 a and 3 b are perspective views of a cyclone inlet accordingto an alternate preferred embodiment of the instant invention;

FIG. 4 is a perspective view of a cyclone separator in accordance withan alternate preferred embodiment of the instant invention, wherein theouter casing of the cyclone separator is transparent;

FIG. 5 is a perspective view of a cyclone separator in accordance withan alternate preferred embodiment of the instant invention;

FIG. 6 is a perspective view of a cyclone separator in accordance withan alternate preferred embodiment of the instant invention;

FIG. 6 a are side views of plates that are used in accordance withalternate embodiments of this invention to divide the interior of acyclone separator into a cyclone chamber and a dirt collection region;

FIGS. 6 b and 6 c are perspective views of plates that are used inaccordance with alternate embodiments of this invention to divide theinterior of a cyclone separator into a cyclone chamber and a dirtcollection region;

FIG. 6 d is a vertical section through a cyclone separator showing analternate position for a plate in accordance with an alternate preferredembodiment of the instant invention;

FIG. 6 e is a vertical section through a cyclone separator showing analternate preferred embodiment of the instant invention wherein theplate is mounted by means of magnets;

FIG. 6 f is a side view of a cyclone separator showing an alternatepreferred embodiment of the instant invention wherein a magnet is usedto assist in particle capture;

FIG. 6 g is a vertical section through a cyclone separator showing analternate preferred embodiment of the instant invention wherein theplate is mounted by mechanical means to the inner surface of the sidewall of the dirt collection chamber wherein the bottom door is closed;

FIG. 6 h is a vertical section through a cyclone separator of FIG. 6(g)wherein the bottom door is open;

FIG. 7 is a vertical section of a cyclone separator showing an alternatepreferred embodiment of the instant invention wherein the bottom of thecyclone casing is raised to form an annular dirt collection chamber;

FIG. 7 a is a vertical section of a cyclone separator showing analternate preferred embodiment of the instant invention wherein thelower portion of the side walls of the cyclone casing have a largerdiameter to form an enlarged dirt collection chamber;

FIG. 7 b is a vertical section of a cyclone separator showing analternate preferred embodiment of the instant invention wherein thebottom of the cyclone casing is raised to form an annular dirtcollection chamber and a longitudinally extending annular dirtcollection chamber is provided;

FIG. 7 c is a vertical section of a cyclone separator showing analternate preferred embodiment of the instant invention wherein aredirector is provided;

FIG. 7 d is a vertical section of a cyclone separator showing analternate preferred embodiment of the instant invention wherein aredirector is provided and the outlet is in the bottom of the cyclonecasing;

FIG. 8 is a perspective view of an array of cyclone separators inaccordance with alternate preferred embodiment of the instant invention;

FIG. 8 a is a top plan view of a construction detail for the array ofcyclones of FIG. 8;

FIG. 8 b is a top plan view of an alternate construction detail for thearray of cyclones of FIG. 8;

FIG. 8 c is a top plan view of an alternate construction detail for thearray of cyclones of FIG. 8;

FIG. 8 d is a side view of the alternate construction detail of FIG. 8c;

FIG. 9 is a top plan view of the cyclone array of FIG. 8 c;

FIG. 9 a is a perspective view of the cyclone array of FIG. 8 c;

FIG. 10 is an exploded perspective view of the cyclone array of FIG. 8 cconstructed as two sequential stages with a common manifold between thestages;

FIG. 11 is a top plan view of the cyclone array of FIG. 8 b;

FIG. 11 a is a perspective view of the cyclone array of FIG. 8 b;

FIG. 12 is an exploded perspective view of the cyclone array of FIG. 8 bconstructed as three sequential stages with a common manifold betweenthe stages;

FIG. 13 is a top plan view of the cyclone array of FIG. 8 a;

FIG. 13 a is a perspective view of the cyclone array of FIG. 8 a;

FIG. 14 is an exploded perspective view of the cyclone array describedin FIG. 8 a constructed as two sequential stages with a common manifoldbetween the stages

FIG. 15 is a schematic drawing of a vacuum cleaner having a plurality ofcyclones in accordance with an alternate preferred embodiment of thisinvention;

FIG. 15 a is an alternate schematic drawing of a vacuum cleaner having aplurality of cyclones in accordance with an alternate preferredembodiment of this invention;

FIG. 16 is a perspective view of a cyclone array removed from a vacuumcleaner wherein the water inlet port is open;

FIG. 17 is a perspective view of a vacuum cleaner wherein the secondcyclonic stage is removed while the first cyclonic stage is retained inposition on the vacuum cleaner;

FIGS. 18 and 19 are perspective views of a vacuum cleaner wherein thefirst and second cyclonic stages are removed and the first and secondcyclonic stages are subsequently separated for separate emptying;

FIGS. 20 and 21 are perspective views of an alternate embodiment of avacuum cleaner wherein the second cyclonic stage is removed while thefirst cyclonic stage is retained in position on the vacuum cleaner

DETAILED DESCRIPTION OF THE INVENTION

The following description of the preferred embodiments of theimprovements in cyclones and arrays of cyclones are described hereinwith reference to their application in a surface cleaning apparatus and,in particular, a vacuum cleaner. It will be appreciated, that indifferent embodiments, the improvements may be used in other householdappliances, such as air cleaners including portable room air cleaners,air cleaners for furnaces and the like, as well as other commercial andindustrial uses including breathing masks, such as for use in hospitalsand in toxic environments and air treatment systems for cars and thelike.

Description of Exemplified Upright Vacuum Cleaner

In a preferred embodiment, the improvements are used in a surfacecleaning apparatus and, preferably, a vacuum cleaner and, morepreferably, a vacuum cleaner having a plurality of cyclonic cleaningstages. A preferred embodiment of a multi stage cyclonic vacuum cleanerthat is used to exemplify the different aspects is shown in FIGS. 1 and2. As shown therein, vacuum cleaner 1 is an upright vacuum cleanerhaving a ground engaging head 2, a main casing 3 pivotally mounted withrespect to ground engaging head 2, a handle 4 for steering vacuumcleaner 1 and an electric cord 5. Main casing 3 has a cyclonic cleaningunit 6 comprising a first cyclonic cleaning stage 7 comprising a singlecyclone and a second cyclonic cleaning stage 8 comprising a plurality ofcyclones 9 in parallel. Dirty air may be introduced into first cycloniccleaning stage 7 by any means known in the art. Referring to FIGS. 1 and2, vacuum cleaner 1 has a ground engaging head 2 having a dirty airinlet (not shown) which is in airflow communication with the first stagecyclone inlet 10. The air travels through first cyclonic cleaning stage7, which is exemplified as comprising a single cyclone, and exitsupwardly via first stage cyclone outlet 27. The air travels upwardly toenter second stage cyclones 9 via second stage cyclone inlets 12. Theair travels through second stage cyclones 9 and exists second stagecyclones 9 via second stage cyclone outlets 13. The treated air thentravels downwardly via conduit 14 into the ground engaging head to afluid flow motor that is preferably a suction motor 15 prior to exitingvacuum cleaner 1.

Ground engaging head 2 may be of any construction known in the art andmay include a rotating brush or the like to assist in entraining dirt inthe dirty air inlet (not shown) in ground engaging head 2. In addition,vacuum cleaner 1 may include an extension wand or the like for above thefloor cleaning as is known in the art. It will also be appreciated thatin an alternate embodiment, vacuum cleaner 1 may be a canister vacuumcleaner, a back pack vacuum cleaner, a carpet extractor, a wet/dryvacuum cleaner, or other vacuum cleaner or surface cleaning equipmentutilized in household and commercial applications which may use asurface cleaning head (i.e. a head that may be used to clean a surfacethat may be a floor, wall, furniture or other surface as is known in theart), and which are preferably used in domestic applications and, inparticular, indoor applications.

Combinations of Cyclones

In accordance with an aspect of the instant invention, which may be usedindividually or with any other aspect, a plurality of cyclonic cleaningstages and, preferably, a plurality of arrays of cyclones are provided.Preferably, such constructions are utilized to remove particulate matterin air, particularly in domestic applications, such as surface cleaningapparatus (e.g. vacuum cleaners, carper extractors and the like) and aircleaners (e.g., portable air cleaners or air cleaners connected to afurnace for a house). As shown in FIG. 2, a vacuum cleaner may has acyclonic cleaning unit 6 comprising a first cyclonic cleaning stage 7comprising a single cyclone, a plurality of second stage cyclones 9 anda plurality of third stage cyclones positioned in pre-motor area 16(e.g. an array 73 as shown in FIG. 8).

It will be appreciated that in an alternate embodiment, the firstcyclonic stage may comprise a plurality of cyclones in parallel. Forexample, a vacuum cleaner may comprise two cyclonic cleaning stageswherein each comprises a plurality of cyclones in parallel, preferablythe first and second stages in order of fluid flow through the vacuumcleaner.

As a further example, suction or air flow motor 15 (e.g., a dirty airmotor) may be positioned upstream from the cyclonic cleaning unit 6,wherein unit 6 may contain 1, 2, 3 or 4 cyclonic cleaning stages. Inaccordance with this example, at least one, preferably a plurality ofand, more preferably, all of the cyclonic cleaning stages comprise aplurality of cyclones in parallel.

Alternately, a cyclone cleaning stage may be provided upstream frommotor 15 and a plurality of cyclonic cleaning stages (e.g. 2, 3 or 4),may be positioned downstream from the suction motor 15. Some, andpreferably a plurality of and, more preferably, all of the cycloniccleaning stages comprise a plurality of cyclones in parallel.

Alternately, a plurality of cyclonic cleaning stages may be providedupstream from the motor and one or more cyclonic cleaning stages may beprovided downstream from motor 15. For example, two or three cycloniccleaning stages may be positioned upstream from the motor 15 and one ortwo cyclonic cleaning stages may be positioned downstream from the motor15. Preferably, some, more preferably most and, most preferably all ofthe cyclonic cleaning stages comprise a plurality of cyclones inparallel.

In a particularly preferred embodiment, four cyclonic cleaning stagesmay be provided upstream from a motor 15 wherein at least one,preferably some and, most preferably all of the cyclonic cleaning stagescomprise a plurality of cyclones in parallel.

Preferably, the cyclonic stages are provided exterior to each other(i.e., not nested). Therefore, they may be stacked (one on top of theother) or positioned side by side.

Construction of Cyclone Inlets

In accordance with another aspect, which may be used individually orwith any other aspect, a cyclone separator 20 may have air inlet 21 thatis located on the top of the separator 20, see for example FIGS. 3, 3 aand 3 b. The inlet 21 may be round, oval, square, rectangular, ellipsoidor any other shape in transverse section to the direction of flow, but arectangular shape, as exemplified in the Figures, is preferred. Theparticle laden fluid represented by arrow 22 enters into the air inlet21 and is directed by the spiral ramp 25 that defines inlet 21 so as tocreate cyclonic circulation 23 in cyclone separator 20. The spiral ramp25 can be configured to occupy an arc of from 10° to 360° of theperimeter of the circumference of the cyclone separator 20 as seen fromabove. Preferably, the spiral ramp 25 extends through an arc from 15 to360° and, more preferably from 25° to 270° and, most preferably from 25°to 90°. In the embodiment of FIG. 3 a, air or fluid inlet 21 extendsthrough an arc of 90° and in the embodiment of FIG. 3 b, air inletextends through an arc of 270°. The spiral ramp 25 may be configured ineither a clockwise or counterclockwise direction. As exemplified in thedrawings, at least a portion of, and preferably all of, inlet 21 ispositioned exterior to the cyclone chamber, which chamber is locatedinside cyclone separator 20. For example, the inlet may be on the outersurface of cyclone separator 20 but is preferably positioned at the topof cyclone separator 20.

Cyclonic circulation 23 in cyclone separator 20 causes at least aportion of the particles 24 within the particle laden fluid stream 22 tobe disentrained from the fluid flow stream and accumulate within thelower region of the cyclone separator 20. The fluid stream 26, whichexits the cyclone separator 20 through the fluid outlet 27 that islocated adjacent to the inlet 21, has a reduced concentration of theparticles 24 than particle laden fluid stream 22. It is understood thatthis construction can be applied to a single cyclone or a plurality ofcyclones in parallel. In another embodiment, it will be appreciated thatoutlet 27 may be provided in the bottom of cyclone separator 20 or anyother location known in the art.

An advantage of having the spiral ramp 25 occupy only a portion of thecircumference of the cyclone separator 20 is that the inlet 21 can bemore readily connected to air intakes, manifolds, or ducts which maylead from the floor engaging nozzle (e.g. a surface cleaning head), fromanother cyclone, a filter bag, a plurality of other cyclones, a fan, apump or other pressure source, or from any other source of particleladen fluid.

Another advantage of this embodiment is that by reducing the arc of theinlet 21, the volume of the inlet is reduced thereby effectivelyincreasing the volume of a cyclone chamber. Accordingly, by using aspiral inlet that extends through an arc less than one full revolution,the volume of a cyclone separator 20, and accordingly, the amount ofdirt which may be contained in the separator 20 may be increased withoutincreasing the outer dimension of the cyclone casing or the appliance inwhich the cyclone casing is provided. It will be appreciated that insurface cleaning appliances, such as vacuum cleaners and carpetextractors, air cleaners and the like, the foot print that the appliancemay occupy is limited. Accordingly, in order to enhance the dirtretaining capacity of the appliance, it is preferred to maximize theavailable dirt collection area without increasing the volume of theappliance. It will be appreciated that in an alternate embodiment, thespiral inlet 21 that extends for less than a full revolution may beconstructed in the side wall of a cyclone bin (see, e.g., FIG. 5).

Internal Screen for a Cyclone Separator

In accordance with another aspect, which may be used individually orwith any other aspect, an improved internal screen for a cycloneseparator 20 is provided, see for example FIG. 4. In this alternativeconstruction, a screen member 28 is preferably constructed from a finemesh having a square area per opening or a hole of 0.000001 to 0.04square inches. The screen openings or holes may be round, oval,triangular, square, pentagonal, heptagonal, or hexagonal or the like andare preferably multisided.

Alternately, or in addition, the screen 28 may comprise a central screen28 a and an outer perimeter screen 28 b that has a longitudinal surfacethat is parallel to the cyclone outlet. The central screen 28 a extendstransversely to extend across the cross section of outer perimeterscreen 28 b so as to provide a complete screen surface extending betweenopposed parts of outer perimeter screen 28 b. Central screen 28 a, whichis a transverse member, may be positioned at the lower terminal end 28′of the outer perimeter screen 28 b (to define a generally squareU-shaped screen), towards the upper terminal end 28″ of the outerperimeter screen 28 but below the entrance to the fluid outlet (todefine a generally square inverted U-shaped screen), or any positionbetween the two, and preferably proximate the midpoint along thelongitudinal length of outer perimeter screen 28 b as exemplified (todefine a generally H-shaped screen). It is preferred that the centralscreen 28 a be positioned between the terminal ends of the outerperimeter screen 28 b so as to form a capture region 29 interior of theouter perimeter screen 28 b to assist in the entrapment of fibers, hairsor particles. Capture region 29 is a cavity interior of the longitudinalsurface, namely outer perimeter screen 28 b, that is open to the fluidin the cyclone separator without passing through the screen. It isunderstood that the cross sectional shape of the screen member 28 may beround, oval, square or any other shape.

As exemplified in FIGS. 2 and 4, the cyclone separator 20 is generallyvertically disposed, the outlet is provided in the top of the cyclonechamber, and the screen 28 comprises a longitudinally extending wall 28b constructed of a screen material (which is preferably circular incross-section) and a transversely extending central screen 28 a which ispositioned interior of the longitudinally extending outer perimeterscreen 28 b, extends across the entire cross-section of the interior ofthe longitudinally extending outer perimeter screen 28 b and between theopposed ends of the longitudinally extending outer perimeter screen 28 bso as to create a shape which is generally H shaped in vertical section.Accordingly, air that has traveled through the cyclone chamber to thebottom of the cyclone casing will travel upwardly through the centralportion of the cyclone and, preferably, enter the capture region 29 ofthe screen 28 (i.e., travel upwardly between the longitudinallyextending outer perimeter screen 28 b). The air will encounter centralscreen 28 a and pass therethrough. If central screen 28 a becomesclogged, then some or all of the air will commence traveling out thelower portion 132 of outer perimeter screen 28 b and may then travelback inwardly through the upper portion 134 of outer perimeter screen 28b towards the centre of the cyclone chamber at a position above centralscreen 28 a so as to travel to the cyclone outlet. Accordingly, the useof a generally H shaped screen in vertical section enhances the amountof screen area which may be utilized.

In accordance with an alternate preferred embodiment, the central screen28 a may be positioned adjacent the bottom of the outer perimeter screen28 b so as to create a screen, which in vertical section, comprises agenerally square U shaped member. Accordingly, the air that is travelingthrough the cyclone chamber towards the cyclone outlet must travelthrough the screen material 28 a or 28 b to reach the cyclone outlet 27.In accordance with this embodiment, the air may travel through thecentral screen 28 a or the outer perimeter screen 28 b so as to reachthe cyclone outlet 27 thereby utilizing the enhanced surface area of thescreen member 28. Accordingly, fluid may travel back inwardly throughthe upper portion 134 of outer perimeter screen 28 b towards the centreof the cyclone chamber at a position above central screen 28 a so as totravel to the cyclone outlet.

In a further alternate embodiment, the central screen 28 a may bepositioned at the top end of the outer perimeter screen 28 b so as tocreate in a vertical section a generally square inverted U shapedfilter. Accordingly, in order to reach the cyclone outlet, the air maytravel upwardly through the capture region 29 interior of outerperimeter screen 28 b to reach the central screen 28 a and to passtherethrough to the outlet 27. Alternately, some of the air may travelthrough the outer perimeter screen 28 b so as to reach the captureregion 29 and to then travel upwardly to the cyclone outlet through thecentral screen 28 a.

In accordance with a further embodiment of the instant invention, theouter perimeter screen 28 b may flare outwardly in a direction away fromthe outlet. Accordingly, a portion of the outer perimeter screen 28 bdistal to the outlet 27 may have a diameter larger in cross section thanthe portion of the outer perimeter screen 28 b adjacent to the outlet.One advantage of this design is that material that accumulates in theinterior volume of the screen is more likely to fall downwardly to thebottom 31 of the cyclone casing when the air flow through the cyclonechamber is terminated. Accordingly, for example, if the cyclone isutilized as a cleaning stage in the surface cleaning apparatus or an aircleaner, the user may remove the dirt collection chamber of the cyclonebin (e.g. the cyclone casing itself may be removed if the bottom 31 ofthe cyclone casing defines the dirt collection chamber) permitting thedirt to flow out of the interior volume of the flared screen into thebottom of the cyclone casing. Alternately, if the screen 28 isremovable, such as is disclosed herein, then the screen 28 may beremoved permitting the dirt that has accumulated in the interior volume(capture region 29) of the flared screen to fall to the bottom 31 of thecyclone casing. Alternately, the screen may be placed over a garbage canand banged against the side to loosen the dirt contained therein andpermit the dirt to fall out of the flared capture region 29.

It will be appreciated that transverse central screen 28 a need not beperpendicular to the longitudinal axis of the outlet conduit 27.

Removable Screen

In accordance with another aspect of the instant invention, which may beused individually or with any other aspect and, preferably, the screenconstruction disclosed herein, a cyclone separator 20 is provided with ascreen 28 that covers all or a portion of the outlet 27 from the cyclonechamber and which is removable and, optionally, replaceable. Inaccordance with this alternate preferred embodiment, the screen 28 isconfigured so as to be removable through or with the fluid outlet 27 ofthe cyclone chamber. For example, as exemplified in FIG. 4, cycloneseparator 20 has an outlet conduit 27 that extends partially into thecyclone chamber and has a screen 28 attached or associated therewith.The screen may have the same diameter as the outlet conduit 27 orslightly less so as to be removable therethrough, or may be larger andremovable with the outlet 27. The outlet conduit 27 may be removablymounted to the cyclone casing, such as by a screw or bayonet mount.Accordingly, a user may remove the outlet 27, and the screen 28 attachedhereto by rotating the outlet conduit 27 and longitudinally withdrawingthe outlet conduit 27 upwardly from the cyclone separator 20.Accordingly, one advantage of this embodiment is that the screen isremovably mounted in the cyclone chamber and may be easily removed topermit the cleaning of the screen. In particular, it is not necessaryfor a user to reach into a cyclone chamber so as to remove the screen orto clean elongate material, such as hair and other fibrous material,from the screen while the screen is mounted in the cyclone chamber.

A further advantage of the instant invention is that outlet conduit 27may function as a handle for the screen. For example, if the outletconduit 27 extends above the top of the cyclone separator 20, the usermay grasp the upper end of outlet conduit 27 and use that as a handle.Accordingly, the user need not touch the screen. Instead, the screen maybe cleaned, by means of a brush and/or washing the screen under water.Once clean, the screen may be reinserted into the cyclone chamberwithout the user touching the screen. It will be appreciated that othermeans known in the art to secure the outlet conduit 27 and the cycloneseparator 20 together may be utilized.

In addition, it will be appreciated that if the screen 28 has a largerdiameter than the outlet conduit 27, then the wall of the cyclone casingin which the outlet conduit 27 is provided will have a removable annularband 30 wherein the diameter of the removable annular band 30 is greaterthan the diameter of the screen 28. Accordingly, when the annular band30 is removed, an opening is provided in the outer wall 30 a of thecasing, which is sized to allow the passage therethrough of the screen28 (see for example FIGS. 2 a and 17). Preferably, the annular band 30forms a one piece assembly with the outlet conduit 27 and may beintegrally molded therewith. Accordingly, only a single element needs tobe removed from the cyclone casing in order to remove the screen forcleaning. Annular band 30 may be lockingly affixed to outer wall 30 a byany means known in the art, such as by a bayonet mount, a screw mount,magnets or locking tabs.

In the embodiment of FIG. 2 a, the first cyclonic cleaning stageincludes a down flow conduit 14. Down flow conduit 14 is collinear withthe fluid outlet 27, extends through the cyclone chamber 53 and has anupper portion 19 positioned above the top of the cyclone separator 20.Accordingly, in this alternate embodiment, the down flow conduit 14 hasan upper end 19 that forms the handle for the unit that is removed. Asexemplified in FIG. 2 a, a user may grasp end 19 and, e.g., rotateconduit 14 to unlock tab 148 from a recess, not shown, and then pullupwardly such that screen 28 is removed leaning an opening 144 in thetop of the cyclone, through which dirt in the cyclone chamber 53 may beemptied.

If a second stage cyclonic stage 8 is mounted on top of the firstcyclonic cleaning stage 7, and the second cyclonic cleaning stageincludes a down flow tube 138, then the second cyclonic cleaning stage 8is first removed. It will be appreciated that end 19 may have a gasketor O-ring 18 to seal down flow tube 138 of the second cyclonic cleaningstage 8 and the upper end 18 of down flow conduit 14 of the firstcyclonic cleaning stage 7.

In accordance with an alternate embodiment, it will be appreciated thatthe screen 28 may be permanently adhered to a screen mount (e.g. it maysurround the outlet conduit 27 of a cyclone chamber and be disposabletherewith). It will be appreciated that as used herein, a screen 28comprises a material that preferably has a generally open pore size,which is selected to permit the passage therethrough of finer dirtmaterial but to prevent the passage therethrough of elongate material.Accordingly, the screen does not filter particulate matter and does notsubstantially affect the back pressure of the air traveling therethroughwhen the screen is clean.

It will be appreciated that the cyclone outlet 27 may be provided atdifferent positions in the cyclone casing and that the orientation ofthe screen in accordance with these embodiments may be accordinglyadjusted so as to cover the outlet 27. Further, transverse centralscreen 28 a need not be perpendicular to the longitudinal axis of theoutlet conduit 27.

Geometry for a Cyclone Separator

In accordance with another aspect, which may be used individually orwith any other aspect, an improved configuration for a cyclone separator20 is provided, see for example FIG. 6. In accordance with thisembodiment, different geometries of cyclone separators 20 are provided.In particular, it is preferred that the geometry of a cyclone separator20 is selected based on the size of cyclone separator 20. According, itis preferred that for cyclone separators 20 that are greater than 1inches in internal diameter (D), the geometry of the cyclone is asfollows:

-   -   the inlet width (W) is preferably between D/3 and D/5,    -   the inlet height (H) is preferably between 2W to 5W, and    -   the height (h) above the floor or bottom 31 of the cyclone        separator 20 is preferably greater than 2H, more preferably more        than 4H and most preferably more than 8H.

If an optional plate 32 is employed, then:

-   -   the height (h) above the plate 32 is preferably greater than 2H,        more preferably more than 4H and most preferably more than 8H;    -   the height (i) below the plate 32 is preferably greater than 1H,        more preferably more than 2H and most preferably more than 4H;        and,    -   the gap between the peripheral wall of plate 32 and the inner        surface of the wall of the cyclone separator 20 is preferably        0.025″ to 0.075″, more preferably 0.035″ to 0.050″, and most        preferably 0.040″.

Alternately, it is preferred that for cyclone separators 20 that areequal to or smaller than 1 inch in internal diameter (D), the geometryof the cyclone is as follows:

-   -   the inlet width (W) is preferably between D/5 and D/15 and more        preferably D/8 to D/12;    -   the inlet height (H) is preferably between 2W to 5W and        preferably 3W to 4W; and,    -   the height (h) above the floor or bottom 31 of the cyclone        separator 20 is preferably greater than 2H, more preferably more        than 4H and most preferably more than 8H.

If an optional plate 32 is employed, then:

-   -   the height (h) above the plate 32 is preferably greater than 2H,        more preferably more than 4H and most preferably more than 8H;    -   the height (i) below the plate 32 is preferably greater than 1H,        more preferably more than 2H and most preferably more than 4H;        and,    -   the gap between the peripheral wall of plate 32 and the inner        surface of the wall of the cyclone separator 20 is preferably 1W        to W/10, more preferably W/1.5 to W/4 and most preferably W/2 to        W/3.

It is understood that for cyclones separators 20 between 0.75″ and 1.5inches in diameter, good but not optimal performance can be achieved byapplying the parameters for cyclone separators 20 smaller or larger than1 inch in diameter.

Configuration of a Divider Plate for Cyclone Separators

In accordance with another aspect, which may be used individually orwith any other aspect, improved configurations for a plate 32 that isincluded in a cyclone separator 20 to divide the interior of a cycloneseparator 20 into a cyclonic region or cyclone chamber 53 and a dirtcollection region or chamber are provided, see for example FIG. 6 a. Asillustrated therein, plate 32 has an upper or cyclone chamber surface 32a, a lower or dirt collection chamber surface 32 b and a peripheral wall32 c. Each of these different configurations beneficially assist incapturing different particle sizes. For example, the peripheral wall 32c of plate 33 is flat (i.e. it may extend generally vertically). Plate33 is preferred for use in a cyclone separator 20 to capture generalparticles found in carpets and homes where the particle size is 3 ormore microns. Alternately, the peripheral wall 32 c may meet upperand/or lower surfaces 32 a, 32 b at an angle. See for example plates 34,35 and 36. As shown, plate 35 comprises an upper portion and a lowerportion that intersect at an intermediate location along the thicknessof the plate so as to define a sharp edge (e.g. it is generally Vshaped). As the size of the particles decreases, plates 33, 34 and 35are more effective in that the discontinuity at the outer perimeterimproves ultra fine particle separation. Alternately, the peripheraledge may be curved (e.g. it may bow out in the centre so as to begenerally C shaped as shown in plate 37). When the specific gravity ofthe particles being removed from the fluid stream is similar to thespecific gravity of the fluid, curved surfaces such as 37, 38, 39, 40,and 41 tend to provide more efficient separation.

It has also been found that for mixtures including a wide range ofparticle specific gravities, creating regular or irregular, symmetricalor non-symmetrical curves or angled discontinuous surfaces on the uppersurface 32 a of the plate 32, i.e. the face disposed towards the cyclonechamber, can enhance separation efficiency. Examples are shown in FIGS.6 b and 6 c. In the example of FIG. 6 b, a discontinuity 42 a curvesupwardly from upper surface 32 a and a discontinuity 42 b curvesdownwardly into upper surface 32 a. In the example of FIG. 6 c, adiscontinuity 43 a is angled upwardly from upper surface 32 a and adiscontinuity 42 b is angled downwardly into upper surface 32 a.

While plate 32 may be mounted transverse to the longitudinal axis of acyclone separator 20 (e.g., if cyclone separator extends vertically,plate 32 extends horizontally), it will be appreciated that in analternate embodiment that plate 32 may be other than in a planetransverse to the longitudinal axis of a cyclone separator 20. Forexample, as shown in FIG. 6 d, the plate 44 is mounted on an anglerelative to the wall 45 of the cyclone separator 20. It is understoodthat the cyclone separator wall 45 may optionally be curved or angledtowards the top or towards the bottom of the cyclone separator 20.

In accordance with a further alternate embodiment of the instantinvention, the plate 32, which may be of any particular configurationand/or one of the configurations disclosed herein, may be positioned soas to define an annular gap between the peripheral wall of the plate 32c and the inner surface of wall 45 of the cyclone casing that is notuniform in thickness. For example, the plate 32 may be closer to thewall 45, or may touch the wall 45, at one or more locations or along inan arc of the wall 45. Alternately, or in addition, the plate 32 may beangled, as shown in FIG. 6 d, such that one end is at an elevateddistance above the bottom 31 of the cyclone casing compared to anopposed end. Accordingly, if the plate 32 is circular and centrallypositioned, the annular gap at the raised end and the lower end will belarger than at the central portion that is not vertically displaced.Alternately, the plate 32 may be angled upwardly from adjacent one arcof wall 45. Alternately, or in addition, it will be appreciated that theplate need not be circular in cross section. Instead, the plate may havean irregular outer surface so as to provide variation in the gap betweenthe peripheral wall 32 c of the plate and the inner surface of wall 45of the cyclone casing.

It will be appreciated that in one embodiment, the plate 32 may besecured to the bottom 31 of a cyclone casing. Alternately, the plate 32may be attached to inner surface 56 of the wall 45 of the cyclone casing(see for example FIGS. 6 g and 6 h).

In an alternate embodiment, instead of a plate 32, the central portione.g., 27 e of FIGS. 7 d and 55 of FIG. 7, of the bottom 31 of thecyclone casing may be raised inwardly so as to define a plateau. Theraised floor 55 may have a continuous wall, e.g., 27 b of FIG. 7 d,which extends downwardly adjacent the periphery of the raised floor 27 eso as to define a side wall, which may be generally vertical, and whichextends upwardly from the floor 52 a of the cyclone bin to the raisedfloor 27 e. Alternately, the side wall 27 b may be recessed underneaththe raised floor. The side wall may have any of the configurationsreferred to above for the peripheral edge 32 c of a plate 32. Inaddition, the raised floor a may be circular in cross section. However,the cross section of the floor may be varied so as to define a variableannular gap between the side wall and the inner surface 56 of the wall45 of the cyclone casing.

Positioning of a Divider Plate for Cyclone Separators

In accordance with another aspect, which may be used individually orwith any other aspect, a passage, all or a portion of which extendsoutwardly, is preferably provided for connecting the cyclone chamber 53in communication with the dirt collection chamber 52. Preferably, asshown in FIGS. 2 and 6 e, the cyclone chamber includes a fluid outlet27, which has a lower end that may comprise an entrance 27 a to thefluid outlet 27, which is positioned above plate 32. The entrance tofluid inlet 27 may be covered by a screen, such as screen 28. The gapbetween plate 32, and the lower extent of fluid outlet 27, or screen 28if provided, may be greater than 0.5″, preferably greater than 1″ and,more preferably greater than 2″. In any such embodiment, the lowerextent of fluid outlet 27 is preferably positioned below the bottom ofcyclone inlet 21. The passage defines a vertical annular gap that has aheight that may be less than 2″ and, preferably less than 1″. In anyembodiment, the height may be less than ⅓, preferably less than ⅙, morepreferably less than 1/10 and, most preferably less than 1/20 thediameter of the cyclone immediately below the bottom of the cycloneinlet 21.

It will be appreciated that the passage may be produced in several ways.For example, the outer circumference of the cyclone casing may beincreased proximate to the height of the raised floor so as to create anouter annular region which functions as a dirt collection chamber. Anexample of such a construction is shown in FIG. 7 wherein a passage 61having a vertical annular gap g and a length RO is positioned betweenthe raised bottom wall 55 and the laterally extending wall 59 b of thecyclone separator 20. In this embodiment the plate (raised floor 55) isformed by a step in the floor 59 a of the cyclone separator 20.

An alternative construction is shown in FIG. 7 a wherein the passage 61having the vertical annular gap g is formed between the plate 54 and thewall 59 b of the cyclone separator 20. The plate may be a molded orformed part and the gap (g) is formed between the plate 54 and the wall59 b of the cyclone separator 20 wherein plate 54 may be affixed to thewall 57 a by support arms 58 extending inwardly from wall 57 a oraffixed to an optional screen member (not shown) which would be affixedor removably affixed to or mounted to, e.g., wall 57 a, wall 45, the topof the cyclone, or a combination thereof. The plate 54 may optionally beheld in place by magnets or other means described elsewhere herein.

Another alternative construction is shown in FIG. 7 b wherein thepassage 61 having a vertical annular gap g is formed between the raisedbottom 55 and the wall 59 b of the cyclone separator 20. A particlecollection region 62 is formed in the annular space between the wall 59and the wall 60. One advantage of this design is that the cyclone may beoriented with its longitudinal axis extending horizontally so thatparticulate matter may accumulate in collection region 62.

Another alternative construction for a plate 32 is shown in FIG. 7 cwherein the passage 61 having a vertical annular gap g is formed betweenthe plate 63 and the airflow redirector ring 64 of the cyclone separator20. In this embodiment the plate comprises a disc attached, e.g., to thecyclone separator floor 59 of the cyclone separator 20. A particlecollection region is marked 66. The airflow redirector ring creates andangle (A) with the wall 65 of, preferably, between 15° to 75° and, morepreferably, 30° to 60° and most preferably 40° to 50°. It is understoodthat the airflow redirector ring 64 can take different geometriesincluding those illustrated as 67, 68, 69, 70, 71 or 72.

Another alternative construction for a cyclone and dirt collectionregion is shown in FIG. 7 d wherein the air exits from the end of thecyclone opposed to the end of the cyclone separator 20 having inlet 21.If the cyclone separator is vertically aligned, then the air enters thecyclone through an inlet air inlet 21 that is located on the top of thecyclone separator 20. The cyclonic circulation 23 causes at least aportion of the particles 24 within the particle laden fluid stream 22 tobecome removed and trapped within the collection region 66 a of thecyclone separator 20. The fluid stream 26 which exits the cyclonethrough the outlet or entrance 27 a to down flow tube 27 c located inthe bottom of the cyclone separator 20 at the end opposite to the inlet21. Thus, a portion of the particles 24 originally entrained in theparticle laden fluid 21 are removed. In this embodiment, the air travelsdown flow director 64 a and then travel downwardly towards laterallyextending wall 27 e. The air then travels outwardly in the passage 61between flow director 64 a and lateral wall 27 e that has a verticalannular gap g2.

The passage may have a height that is less than ⅓ the diameter,preferably, less than ⅙ the diameter, more preferably less than 1/10 thediameter and most preferably less than 1/20 the diameter. Accordingly,the height may be 2 inches or less and preferably 1 inch or less. In aparticularly preferred embodiment, preferably, the height of the gap (g)is 0.015″ to 0.250″ for cyclones larger than 1 inch in diameter D,especially for use in vacuum cleaners. A radial overlap (RO) thatdefines the length of the passage 61 is defined by the overlap of theraised bottom floor or plate and the outwardly extending portion 59 b ofwall 59 of the cyclone separator and/or the flow director. Preferably,this radial overlap is 0.015″ to 0.250″ for cyclones larger than 1 inchin diameter D. Preferably, the height of the gap (g) is 0.002″ to 0.040″for cyclones smaller than 1 inch in diameter D, and raised bottom floor55 extends outwardly to extend slightly underneath the lower portion 59b of wall 59. More preferably the radial overlap between the lowerportion 59 b of wall 59 and the outer radial edge of the raised floor 55is 0.005″ to 0.125″ for cyclones equal to or smaller than smaller than 1inch in diameter D. In an alternate embodiment exemplified in FIG. 7 d,it has been found that the gap g2 is preferably 0.025″ to 0.075″ forcyclones greater than one inch in diameter D for collecting particlesbetween 4 and 100 microns in size. It has been found that the gap g2 ispreferably 0.025″ to 0.075″ for cyclones greater than one inch indiameter D for collecting particles between 4 and 100 microns in size.It has been found that the gap g2 is preferably 0.005″ to 0.040″ forcyclones smaller greater than one inch in diameter D for collectingparticles between 0.1 and 10 microns in size, and more preferably 0.015″to 0.025″.

It is also understood that the dimensions of the gap (g) and the radialoverlap may be varied around the perimeter of the raised bottom wall 55to create conditions which are optimal for the collection of a band ofparticle sizes or particle densities.

The distance between the floor of the dirt collection region and thebottom of flow director 64 a is preferably not less than the height ofthe inlet H2 and the height of section 27 c is preferably greater than2H, more preferably 4H and most preferably greater than 8H and the gapg3 between the bottom of the inlet 21 and the top of the down flow tubesection 27 c is preferably 0.5H2 to 1.5H2, and more preferablyapproximately 0.9H2. The internal area of the down flow tube 27 c ispreferably at least equal to the area of the spiral inlet 21 and morepreferably is 1.5 to 2.5 times larger than the area of the spiral inlet21. This cyclone design may optionally incorporate an airflow redirector64 a, which may be shaped as 67, 68, 69, 70, 71 or 72 or any similarshape, which creates a barrier to the re-entrainment of particles 24captured in the region 66 a.

The height of the gap (g2) is preferably 0.002″ to 0.040″ for cyclonessmaller than 1 inch in diameter D, and the radial overlap RO2 betweenthe airflow redirector ring 64 a and the edge of the down flow tube 27 bis preferably 0.005″ to 0.125″ for cyclones equal to or smaller thansmaller than 1 inch in diameter D. It is also understood that thedimensions of the gap (g2) and the radial overlap (RO2) may be variedaround the perimeter of the down flow tube 27 b to create conditionswhich are optimal for the collection of a band of particle sizes orparticle densities.

In alternate embodiments, a cyclone separator 20 having a passage 61 maybe used as a particle filter in the outlet conduit from a combustionchamber, preferably downstream from the outlet of a wood stove, afurnace, a car engine and a producer gas unit (partial oxidationreactor).

Moveable Divider Plates for a Cyclone Separator

In accordance with another aspect, which may be used individually orwith any other aspect, it is understood that plate 32 may bepermanently, removably, translatably or pivotally affixed in cycloneseparator 20, such as by being permanently, removably, translatably orpivotally affixed to screen 28 or side wall 45.

The plate 32 may be held in position by means of magnets and or magnetsmay be used to assist in particle capture. For example, the plate 32 mayhave one or more magnets provided thereon and positioning magnets may beprovided over and/or below the plate 32 wherein the faces of thepositioning magnets that face the plate 32 have the same polarity as thefaces of the magnet or magnets on plate 32 which are spaced from butfacing the positioning magnets. Accordingly, the plate 32 may be held inplace by magnetic repulsion. Alternately, it will be appreciated thatthe plate may be held in position by magnetic attraction.

FIG. 6 e exemplifies a construction wherein a plate magnet 46 is affixedto or embedded within the plate 47 and is magnetically suspended betweenthe positioning magnets 48 and 49 by means of magnetic repulsion. Themagnet 49 may be affixed to or embedded within the floor 50 of thecyclone separator 20. One advantage of this construction is that themagnets 46, 47, 48 and 49 create a magnetic field within the cyclonechamber to enhance the collection of magnetic and paramagneticparticles.

If the floor 50 is removable or moveable (e.g. pivotally mounted such asby pivot hinge 50 a as shown in FIG. 2 a), then when dirt collectionchamber 52 is opened (e.g. floor is pivoted open), the plate 47 could beremoved (e.g., if it is not attached by any means to the cycloneseparator it would fall out) or if it is mechanically retained (notshown) it could be translated some distance either vertically,laterally, or both to facilitate the removal of particles collected bothin the cyclone chamber 51 above plate 47 and in the dirt collectionregion 52 below plate 47.

Similarly, if upper positioning magnet 48 is associated with a screen(not shown), such as by being affixed thereto or embedded therein, andthe screen is removed through or with the outlet 27, plate 47 could beremoved or if it is mechanically retained (not shown) it could betranslated some distance either vertically, laterally, or both tofacilitate the remove of particles collected both in the main collectionregion 51 and in the dirt collection region 52. Alternately, plate 32may be moveable when a door, e.g., a bottom opening door 50, is pivotedopen about, e.g. pivot hinges 50 a. Accordingly, plate 32 may be securedto inner surface 56 of wall 45 of the dirt collection chamber 52 by anymeans known in the art, such as by a pivot hinge 158 (see for exampleFIGS. 6 g and 6 h). Plate 32 may be supported in a generally horizontal,or other desired, position by a column 160 extending upwardly from door50. When door 50 is opened, such as by pushing button to move lever 164outwardly and release the engagement of flange 166, and which may be byany means known in the art, plate 132 may pivot down, e.g., to aposition generally parallel to or, as exemplified, inclined with respectto the axis of the cyclone separator.

It is understood that the plate 47 may be any type of plate includingbut not limited to those described in FIGS. 6, 6 a, 6 b, 6 c and 6 d. Itis also understood that this configuration may be employed with any topinlet or a side wall inlet cyclone geometry. It is understood thatmagnetic attraction to another magnet or to a magnetically permeablematerial such as steel may also be used to movably or removably fix theplate 47 in position. It is also understood that a single positioningmagnet may be used to produce a repulsive or attractive force to forcethe plate 47 against a fixed, movable or removable stop therebypermanently, movably or removably fixing the plate into position. Anadvantage of magnetic mounting is that the translation of the plate 47to facilitate the removal of trapped particles makes cleaning such aunit much easier.

Magnetic Separation

In accordance with another aspect, which may be used individually orwith any other aspect, one or more magnets may be provided in an airflow passage so as to assist in attracting and retaining metallic andparamagnetic particles. For example, one or more magnets may be providedadjacent the inlet or outlet, or inside the inlet or outlet, of acyclone. Alternately, or in addition, it will be appreciated that one ormore magnets may be provided at any desired location inside a cyclonechamber, or exterior to a cyclone chamber or air flow passage, providedthat the magnetic field extends inside the cyclone chamber or air flowpassage.

In accordance with another embodiment of the instant invention, one ormore magnets may be removably attached to the plate 47, the cycloneseparator 20 and/or an air flow passage. When the magnet is removed,magnetic particles that have accumulated may fall off any surface towhich they are adhered by magnetic force and/or may be removed bymechanical means. Accordingly, removal of the magnet assists in cleaningthe cyclone separator.

For example, as exemplified in FIG. 6 f, a cyclone separator 20 has amagnet 49 a affixed to the floor 50, and optionally to the wall, (notshown) to assist in the collection of metallic and magnetic particleswherein the magnet 49 a can be translated away from or removed from thefloor 50 thereby eliminating the magnetic influence and allowing theparticles captured in the cyclone separator 20 to be easily removed byeither removing the floor 50 or by removing the inlet/outlet elementsand pouring the contents of the cyclone.

Cyclone Separator Arrays

In accordance with another aspect, which may be used individually orwith any other aspect, an array of cyclones is provided. Referring toFIG. 8 a plurality of parallel cyclones 73 is provided, which may be ofany construction know in the art or described elsewhere in thisspecification, and preferably are designed and configured to create ahigh separation efficiency and a high airflow rate with a minimumback-pressure. Preferably, the array comprises a large number ofcyclones 73 in parallel. In particular, the array may comprises morethan 1 cyclone per square inch, preferably more than 4 cyclones persquare inch, more preferably 9 or more cyclones per square inch suchthat high airflow rates and high separation efficiencies for very smallparticles can be achieved. If the array is designed to separateparticles smaller than 1 micron, the use of cyclone densities of 9 to 64cyclones per square inch is preferred. Such arrays may be useful as apre and/or post motor filter in a vacuum cleaner or in a breathing mask.For example, such an array may be positioned in the pre-motor area 16(see FIG. 2).

Alternately, or in addition, an array of cyclones may be of variousconstructions to increase the compactness of the cyclone array or toincrease the efficiency of the cyclone array. As exemplified in theembodiment of FIG. 8 a, the construction of a cyclone array may employ acommon wall between some and preferably all of the cyclones as shown inFIG. 8 a where three cyclones 74, 75 and 76 within the array 73 areshown with a portion of their walls overlapping in areas 77 and 78 toallow a very compact geometry. Alternately, or in addition, theconstruction of a cyclone array 73 can employ a touching wall betweensome, and preferably all, of the cyclones. An example is shown in FIG. 8b where three cyclones 79, 80 and 81 are positioned with their wallstouching at positions 82 and 83, which creates a stronger constructionwith fewer cyclones. Alternately, or in addition, the construction of acyclone array 73 may employ spaced apart cyclone walls as shown in FIG.8 c where the cyclones 84, 85, 86, 87, and 88 are spaced apart whichmakes them easier to mold. An advantage of spacing the cyclones apart isthat the space between the cyclones 84, 85, 86, 87, and 88 may form aregion 89 where further particle collection can occur as the air travels(e.g., “spins”) to enter the cyclonic inlets of each individual cyclone(e.g., if a manifold is provided which covers all of the cyclone inlets)as opposed to each inlet being connected directly to a fluid flowconduit. If the common floor 90 between the cyclones 84, 85 and theothers from FIG. 8 is moved to the bottom of the cyclones 91, thecapacity of the annular space 89 for the collection of fine particleswill be increased. Preferably, the cyclone arrays described in FIGS. 8,8 a, 8 b, 8 c and 8 d are constructed using one or more of theconfigurations described in FIGS. 7, 7 a, 7 b, 7 c, and 7 d.

If an array of cyclones is provided, then the cyclones are preferablycleaned by passing water therethrough. Accordingly, at least one waterport may be provided to permit water to enter or exit the cyclone array.For example, as shown in FIG. 16, water inlet port 114 may be providedwith a closable cap, or other closure member, 116. Water inlet port 114is preferably provided on top surface 108 and is in communication withthe fluid flow passage leading to the cyclones (e.g., the dirty air flowpassage in a vacuum cleaner extending to the cyclone inlets). The inletspreferably are downstream from a header 130 and the water inlet port 114is provided in the header. When cap 116 is open, a user may pour waterinto port 114. The water will flow through a passage to the cyclones.The user may then use handle 118 to move away, e.g., in a swirlingmotion. Thereafter, the water may be drained, e.g., by pushing button122 that moves lever outwardly so that bottom door 120 pivots open topermit water and suspended dirt to be removed by passing downwardly outof bottom of stage cyclones 9 (see for example FIG. 20).

In accordance with this aspect, a plurality of cyclones in parallel maybe provided wherein the cyclones have at least two dirt collectionchambers, wherein the at least two dirt collection chambers are emptiedat the same time. For example, the dirt collection chambers may have acommon bottom 120 that is openable. Preferably, as exemplified in FIG.20, each cyclone has a dirt collection chamber and all of the dirtcollections chambers have a single common door so that, by opening asingle door, all of the chambers are emptied at the same time. Forexample, in the embodiment of any of FIGS. 9, 9 a, 10, 11, 11 a, 12, 13,14, the bottom 120 (not shown) may be pivotally mounted to peripheralwall 92 such that all cyclones are emptied concurrently.

The surface cleaning apparatus may have two cleaning stages wherein oneof the stages, preferably the second, comprises a plurality of cyclonesin parallel. The other cleaning stage, preferably the first cleaningstage may be any filtration or dirt collection member known in the art.It will be appreciated that, in another aspect, the surface cleaningapparatus may have only one cyclonic cleaning stage comprising aplurality of cyclones in parallel wherein the plurality of cyclones areremovable as a unit, preferably with the associated dirt collectionchamber or chambers.

In accordance with this aspect, it is preferred that two cyclonic stagesare provided wherein at least one comprises a plurality of cyclones inparallel and the stages are emptied separately. For example, as shown inFIG. 17, second cyclonic cleaning stage 8, which comprises a pluralityof cyclones in parallel, may be removed from vacuum cleaner 1 while thefirst stage cyclone 7 is retained in position in vacuum cleaner 1. Thesecond cyclonic cleaning stage may be slidably mounted on flanges 126that are received in L-shaped members 128 that are provided on thebottom panel of the stage 8, which is preferably a pivoting door 120.Accordingly, when second cyclonic cleaning stage 8 is removed, e.g.,slide in the direction of arrow A, it may be carried to a garbage can,button 122 pressed and door 120 opened so that the second stage cyclones9 may be emptied. Any locking member known in the art may be used tosecure second cyclonic cleaning stage 8 in position on the vacuumcleaner and to connect the cyclone array 156 in air flow communicationwith the respective passages in the surface cleaning apparatus. Forexample, the cyclone array may be sealed in position by means of angledseals, a lifter mechanism or other sealing means known in the art. Itwill be appreciated that this design may be used if the vacuum cleaneronly has one cyclonic cleaning stage.

Alternately, as shown in FIGS. 18 and 19, first and second cyclonicstages 7, 8 may be removed at the same time from the vacuum cleaner 1.Cyclonic stage 7 may then be emptied, e.g., by opening a bottom pivotingdoor 50. The cyclonic stages 7, 8 may first, or subsequently, beseparated, such as by rotating cyclonic stage 8 relative to cyclonicstage 7 in the direction of arrow B as shown in FIG. 19. The secondstage 8 may then be emptied. It will be appreciated that stages 7 and 9may be emptied in any particular manner known in the art, such as by abottom pivoting door or the dirt collection chamber being removed fromthe cyclone chamber.

In accordance with this aspect of the invention, it is preferred thatthe cyclone array is removed as a sealed unit, other than the other thanfluid flow passages leading to and from the cyclones. For example, asshown in FIG. 2, air that exits the first stage cyclone 7 travelsupwardly from outlet 27, through opening 150 in bottom 120 to one ormore openings 148 in the bottom of second cyclonic cleaning stage 8 (SeeFIG. 20) that are upstream of header 130 and are connected thereto by aconduit. The air travels through the cyclones 9 and exits secondcyclones 9 via outlets 13 to header 136 and then to down flow tube 138,which is upstream of conduit 14 and exits second cyclonic stage 8 viaopening 152 in bottom 120. Thus, when second stage 8 is removed from thevacuum cleaner and/or the first stage, second stage 8 is sealed, otherthen the one or more openings in the bottom of second cyclonic cleaningstage 8 and the bottom 140 of down flow tube 138. The array may have afilter that is removable therewith.

Another removal method is exemplified in accordance with the embodimentof FIGS. 20 and 21, wherein housing 154 of second cyclonic stage 8 ispivotally mounted to bottom 120 and, when opened, cyclone array 156 maybe pulled downwardly out of housing 154 for emptying. Alternately, itwill be appreciated that the top of housing 154 may pivot upwardly orotherwise open to permit cyclone array 156 to be pulled upwardly out ofhousing 154. It will be appreciated that, if the cyclone array 156 ispreferably a sealed unit, then a bottom opening panel, with holesaligned with conduits 138 and 146, may be provided. In an alternateembodiment, the housing 154 may pivot upwardly leaving cyclone array 156in position on top of the first stage cyclone 7 (or other filtrationmember or housing member). A consumer may then pick up cyclone array156, such as by a handle, and remove it for emptying. It will beappreciated that this design may be used if the vacuum cleaner only hasone cyclonic cleaning stage.

Transfer of Material Between Cyclone Stages

In accordance with another aspect, which may be used individually orwith any other aspect, a plurality of cyclones are configured such thatmaterial that is disentrained by one cyclone is conveyed to anothercyclone by introducing the separated material into the fluid flow streamthat travels to the other cyclone. An example of such an arrangement isshown in FIG. 15. As shown therein, a fluid flow duct 1501 branches intoducts 1502 and 1503, which in turn lead to cyclones 1504 and 1505. Thefluid flowing within duct 1501 continuously or periodically contains oneor more types of particles or other materials 1512 which are desired tobe removed from the fluid flow stream. The cyclone separators 1504 or1505, may be any cyclone separators or combination of cyclone separatorsknown in the art, or any individual cyclone design or combination ofcyclones described within this specification including but not limitedto top inlet cyclones, side wall inlet cyclones, bottom inlet invertedcyclones and cyclones with plates. Optionally, the particles 1512collected in the cyclone separator 1504 are continuously or periodicallytransferred into the ducts 1501 and/or 1503 by means 1514 so that overtime most of the particles are collected in cyclone 1505 other thanthose which pass to an optional particle separation member 1510 due tothe efficiency limitations of cyclones 1505 and 1504. Optionally, theair outlet 1506 from cyclone 1504 passes through duct 1507 to theoptional particle separation member 1510, which is adjacent to thesuction source 1511.

One advantage of this configuration is that, when used, e.g., in avacuum cleaner, the transfer of particles from cyclone 1504 to cyclone1505 allows the user to empty a single container, which simplifiesemptying the vacuum cleaner.

In an alternate embodiment, material collected may be conveyed tocontainer 1513. This container 1513 may be reusable or disposable, madeof one or more organic or inorganic polymers, rubber, plastic, paper,cardboard, glass or metal, or any combination thereof, and be in theform of a bag, box, bottle, jar, bin or any other closed or semi closedform for easy disposal of the particles or transfer of the particles forother uses or operations. Accordingly, an advantage of this alternateembodiment is that a single automated mechanism may be used tocontinuously or periodically transfer the collected particles 1512 intoa container 1513 as controlled by particle transfer means 1515.

It is understood that the container 1513 could optionally be fully orpartially closed or sealed by the action of the user or optionally beautomatically partially or fully closed or sealed by the mechanism ofthe system when the user initiates or carries out the release or removalof the container 1513. The container 1513 is preferably designed tocontain most or all of the particles 1512. It is understood that thecontainer 1513 or a portion of the container 1513 need not be gas orliquid tight but that it may be porous or contain a porous area ormember which may optionally facilitate the entry and or exit of fluids,to optionally facilitate the disinfection of the container 1513 and/orits contents by the use of chlorine gas, ozone gas, pure oxygen or otheragents, to optionally facilitate the compacting of the container 1513and/or its contents by allowing gases to escape, and/or facilitates thecontainer 1513 and/or its contents to biodegrade.

The particle transfer means 1514 may consist of a door mechanism whichperiodically opens to allow the particles to fall into a region fromwhich the particles 1512 are drawn into ducts 1501 and/or 1503, duringwhich time the suction source 1511 may either be turned off or itsinfluence on cyclone separator 1504 interrupted such as by a valve 1516.The particle transfer means 1514 may alternately comprise a rotatingmember similar to a revolving door disposed vertically, horizontally, orat any angle which continuously or periodically transfers particles 1512into a region from which the particles are conveyed by gravity orconveyed by means of a mechanism such as a screw or plunger into theduct member 1501 and/or 1503 by means of the duct members 1518 and 1517respectively during which time the suction source 1511 may either beturned off or its influence on cyclone separator 1504 may optionally beinterrupted by an optional member such as a valve 1516.

The particle transfer means 1515 may be the same as or different fromparticle transfer means 1514 transferring particles 1512 to container1513 by means of the duct member 1519 during which time the suctionsource 1511 may either be turned off or its influence on cycloneseparator 1505 may be optionally interrupted by an optional member suchas a valve 1520.

The particle transfer means 1514 and 1515 may alternately each comprisea door that opens and closes periodically or by the action of the user,a vibratory plate, or a vibratory plate in combination with a valve ordoor.

It is understood that the operation of transferring the particles fromcyclones 1504 and 1505 may be continuously actuated; automaticallyactuated on a periodic basis; actuated or halted in response to aparticle level within the cyclones or within the container 1513;actuated in response to a sensor; actuated by the interaction of theuser with the system such as attempting the removal of the cyclone 1505;the optional container 1513, or by the powering up or powering down ofthe system, or by a combination of one or more of these methods.

It is also understood that this invention can be applied to groups orarrays of cyclones wherein 1504 and 1505 represent a plurality ofcyclones in parallel rather than a single cyclone.

It is understood that the optional particle separation member 1510 maybe a cyclone, a plurality of parallel cyclones, two or more cyclonesconnected in series, two or more cyclonic stages wherein each cyclonicstage comprises a plurality of cyclones in parallel, two or morecyclonic stages wherein each cyclonic stage comprises a plurality ofcyclones in parallel and each individual cyclone in an upstream array ofcyclones in parallel is in series fluid flow communication with a singlecyclone of the downstream array of cyclones in parallel, two or morecyclonic stages wherein each cyclonic stage comprises a plurality ofcyclones in parallel and each individual cyclone in an upstream array ofcyclones in parallel is in series fluid flow communication with morethan one cyclone of the downstream array of cyclones in parallel (e.g.preferably two), two or more cyclonic stages wherein each cyclonic stagecomprises a plurality of cyclones in parallel and each individualcyclone in an upstream array of cyclones in parallel is in series fluidflow communication with a manifold which feeds at least one cyclone ofthe downstream stage, a fibrous filter media, a fibrous media with anadhesive or surface treatment applied to aid in fine particle capture orretention, or a liquid bath through which the fluid stream must pass.

It is also understood that the optional particle separation member 1510may be physically adjacent to the suction source 1511 or that it may beconnected to the suction source 1511 by means of a duct or passage way,which may include one or more bends. It is also understood that theoutlet of the cyclones may be through the bottom or side wall of thecyclone, or a combination thereof. It is also understood that the fluidflow 1501 may come from a floor nozzle of a vacuum cleaner or otherfloor cleaning device, from the wand or hose of a vacuum cleaner orother cleaning device, from the air in a room, from a fluid wherein oneor more particles sizes or types is to be separated, from another sourcesimilar to those described above with reference to optional particleseparation member 1510 or from a liquid bath through which the fluidstream must pass.

An alternate embodiment of a plurality of cyclones that are configuredsuch that material that is disentrained by one cyclone is conveyed toanother cyclone by introducing the separated material into the fluidflow stream that travels to the other cyclone is exemplified in FIG. 15a. FIG. 15 a shows a fluid flow duct 1501, which leads to cycloneseparator 1505. The fluid flowing within duct 1501 continuously orperiodically contains one or more types of particles or other materials1512 which it is desired be removed from said fluid flow stream. Thecyclone separator 1504 may be designed to capture finer particles moreefficiently as it is in series with and downstream of cyclone separator1505.

The particles 1512 collected in the cyclone separator 1504 arecontinuously or periodically transferred by means 1514 into the duct1501 so that over time more of the particles collect in cyclone 1505.

The particle transfer means 1514 operates exactly as described withrespect to FIG. 15 except that it only feeds into fluid flow duct 1501by means of duct member 1518. The particle transfer means 1515 operatesexactly as described with respect to FIG. 15 except that in operationvalve 1516 would be used to optionally disrupt the influence of suctionsource 1516 on cyclone 1505 as the cyclones 1504, 1505 are in series.

The air outlet 1506 from cyclone 1504 passes through duct 1507 to theoptional particle separation member 1510, which is adjacent to thesuction source 1511. It is also understood that an optional particleseparation member 1510 a, which is adjacent to the outlet of the suctionsource 1511 can also be provided. It is understood that the members 1510and 1510 a may optionally be removed together for cleaning and may beplaced mechanically adjacent to each other. It is understood that theoptional particle separation member 1510 or 1510 a may be the same asdescribed with respect to FIG. 15.

It is also understood in this invention that the optional particleseparation member 1510 or 1510 a may be physically adjacent to thesuction source 1511 or that it may be connected to said suction by meansof a duct or passage way which may include one or more bends. It is alsounderstood that the outlet of the cyclones way be through the bottom orsidewall of the cyclone, or a combination thereof.

It is also understood that the fluid flow 1501 may come from any sourceas described with respect to FIG. 15.

It is also understood in this invention that the cyclone separators 1504and 1505 may each represent a single or a plurality of parallelcyclones, and that this invention may be applied to more than twosequential cyclones so that the particles 1512 are collected in a numberof cyclones or cyclone stages which is less than the total number ofcyclones or cyclone stages. It is also understood that 1510 or 1510 amay themselves be a plurality of cyclones mounted into the wall or theportion of the wall of a larger cyclone thereby creating a structurewhich minimizes energy losses in connecting ducts. It is also understoodthat the structures described in FIGS. 15 and 15A can be configured toremove nano-sized particles and live virus particles.

Transparent Plastic Sections

In accordance with another aspect, which may be used individually orwith any other aspect, a surface cleaning apparatus has a plurality ofcyclones in parallel 9 having at least one dirt collection chamber 52wherein at least a portion of the dirt collection chamber below themaximum fill position (which may be a maximum fill line marked on thehousing) is transparent.

For example, in the embodiment of FIG. 2 a, second stage cyclones eachhave a dirt collection chamber 52 having an outer wall 100 that istransparent. Further, cyclone chamber 102 has an outer wall 104 that istransparent. Second stage cyclones 9 are provided within a casing orhousing having a side wall 106 and a top wall 108 which are transparent.Provided that a portion of side wall 106 that is outward of the maximumfill line of dirt collection chamber 52 is transparent, then a user mayview the maximum fill line or position and determine when to empty thesecond stage dirt collection chambers 52. It will be appreciated that,as exemplified, each of the second stage cyclones and the second stagecyclone housings may be made from transparent plastic (which may beshaded or tinted but still permit a user to see therethrough) and thatpart may be masked by a label or coating so as to render part thereofopaque. Provided the user can view when the dirt collection chamber(s)52 are full, the user will have a visual signal to clean or empty thesecond stage cyclones. This design is particularly preferred when theplurality of cyclones 9 has an associated plurality of dirt collectionchambers 52, and preferably each cyclone 9 has an associated dirtcollection chamber 52, and, particularly, when the cyclones 9 areemptied separately from another cleaning stage.

Alternately, or in addition, a filter 112 (e.g., foam, HEPA, etc.) maybe provided in a housing 110 wherein at least a portion of the housingthat is visible, or may be made visible, is transparent. Preferably, allof housing 110 is transparent plastic. This permits a user to noticewhen filter 112 is dirty and requires cleaning or replacement.preferably, housing 110 is a pre-motor filter. Accordingly, for example,housing 112 may be provided in pre-motor area 16. Thus when cycloniccleaning unit 6 is removed, a user can view housing 110, e.g., the topthereof. However, it will be appreciated that filter 112, which is notprovided in the cyclone chamber, may be visible through a transparentside wall of the vacuum cleaner or may housing 110 may be visible when adoor that is provided in the vacuum cleaner is opened. An advantage ofusing a housing is that the consumer need not touch filter 112 whenremoving filter 112 from the vacuum cleaner.

It will be appreciated that one or more filters (e.g., foam) may beremovable with the cyclone array 156 and that these may be provided in ahousing, a portion or all of which is transparent.

Uses

It is also understood that any or all of the embodiments may be usedindividually or in combination or sub-combinations. In addition to theiruse in surface cleaning appliances and other domestic appliances andbreathing masks, they may also be used, singly or in combination, inother applications.

For example, the cyclonic embodiments described herein may be used inconjunction with a fan or other air moving means to create a sweeper, asweeper with suction, a vacuum cleaner, a canister vacuum cleaner, anupright vacuum cleaner, a wet/dry vacuum cleaner, a stick vacuumcleaner, a carpet shampooer, a carpet extractor, a hand vacuum, a backpack vacuum, a vehicle mounted vacuum, or any other type of vacuumcleaner or dust extractor or to pick up unwanted particles and tosubsequently remove unwanted particles from air.

Alternately, the cyclonic embodiments described herein may be applied tothe inlet for cooling air to, and/or the outlet of air from, computers,electronic equipment, or mechanical equipment to protect a computer orequipment from particles, which may damage them or impair theirfunction.

It is also understood that the cyclonic embodiments described herein maybe used in conjunction with a fan or other air moving means to create anair cleaner, air purifier, airborne particle capture system, fan with aparticle capture system, automotive cabin air filter, heating, coolingor ventilation system to capture unwanted particles from an air stream.

It is also understood that the cyclonic embodiments described herein maybe used in conjunction with a fan or other air moving means to create afilter mask to capture unwanted particles from an air stream. A filtermask constructed with the cyclones descried in this specification orwith any cyclones known in the art may be designed to filter the airthat a person breathes in, breathes out, or both, so as to be able tocreate a portable means of isolating a person from their surroundingenvironment. A small fan may optionally be used to reduce the pressurethat the person must exert with their lungs to breathe in and/or outthrough the cyclonic means.

It is also understood that the cyclonic embodiments described herein maybe used in conjunction with a fluid moving device to create a means ofremoving unwanted particles from fluid. The cyclonic embodimentsdescribed in this specification may be placed in the duct leading to thefluid moving member, either directly adjacent or some distance away, toprotect the fluid moving member from the particles and to remove them.The cyclonic embodiments described herein may alternately or also beplaced in the duct leading from a fluid moving member, either directlyadjacent or some distance away, to protect equipment downstream from thefluid moving member from the particles which the fluid moving member mayintroduce to the fluid stream. The positioning of the cyclonicembodiments described herein may be mechanically arranged so that theycan both be removed for cleaning or servicing together.

It is also understood that the cyclonic inventions described herein maybe used to reduce the particle emissions from any type of burner used toheat homes, heat water, and to remove emissions from the exhaust gassesfrom industrial processes, the exhaust gasses from internal combustionengines, the exhaust gasses from external combustion engines and theexhaust gasses from turbine engines. The cyclonic embodiments describedherein may be placed in the duct leading to or from the emission source,either directly adjacent or some distance away, to protect the particleemission causing device from particles in the air stream which theyrequire to operate. The cyclonic embodiments described herein mayalternately or also be placed in the duct leading from the particleemissions source, either directly adjacent or some distance away, toprotect equipment downstream from the emissions source and theenvironment from the particles which the emissions source may introduceinto its exhaust stream.

The advantage of the multi stage cyclonic separation means describedherein is that a vacuum cleaner, filter mask or other apparatusmentioned herein may be produced which can optionally reach HEPA or ULPAseparation levels without the use of a filter.

The cyclonic separation means employed in this manner may be cleaned ordisposed of, or a combination thereof.

Optional Fluid Flow Motors

The fan means used in any aspect may be a two to ten stage fan systemoperating from one or more motors in series or in parallel and the fanmay be a propeller, an impeller, a Prandtl layer turbine also known as aTesla turbine, or a combination thereof.

Optionally, the vacuum cleaner may be powered by means of a Stirlingengine, a steam engine, or an internal combustion engine wherein saidStirling engine, steam engine, or internal combustion engine mayoptionally be operated from hydrogen gas produced by electricity fromthe wall or from a battery or produced by a chemical reaction or whichmay optionally be withdrawn from a storage vessel. The option tomanually or automatically switch the hydrogen source powering the vacuumfrom one source to another may be provided. It is to be appreciated thata hydrogen powered appliance, including surface cleaning apparatus andother appliances for indoor use, may operate using any design known inthe respective arts.

Hydrogen produced by electricity when an appliance, e.g. a surfacecleaning apparatus, preferably a vacuum cleaner, is plugged into anelectric outlet may be used to power the surface cleaning apparatus. Allor a portion of the hydrogen may be stored for cordless operation. Itwill be appreciated that some hydrogen may be used as it is generated tooperate the device. Such a hydrogen powered surface cleaning apparatusmay be used alone or in combination with any other embodiment disclosedherein. The hydrogen produced by electricity when the vacuum is pluggedin but not being used is a preferred method of operating. The storagemeans contemplated is any means known in the art including but notlimited to pressurized storage, storage in a metal hydride or otheradsorptive storage means. The hydrogen stored may be produced by fuelreforming, chemical reactions or by electrolysis. Alternately, or inaddition, a central hydrogen generator which charges a small portable“vessel” which is plugged into the air cleaning device may be provided.

Adhesive Member

It is also understood that in any embodiment, an adhesive material suchas agar or pectin or a rubber based adhesive may be applied to the allor a portion of interior surfaces of cyclone separator 20 to assist inthe capture and retention of fine particles. For example, the adhesivecan be applied to the interior and exterior of the down flow tubes 27 band 27 c and/or plate 32 which may be removed for cleaning when thebottom of the cyclones is removed or this section may be disposed of andreplaced with a clean piece with fresh adhesive. Alternately, or inaddition, the mesh used to construct the screen 28 may incorporate anadhesive or micro-filaments, which aid in the entrapment of fibers,hairs or particles. Accordingly, if the screen 28 comprises an adhesivematerial, it will be appreciated that the screen 28 may be disposable.

This embodiment is particularly useful in cyclone separators where smallquantities of fine particles are to be collected such as in the second,third, or fourth or other sequential stages of a multistage cycloneseparator. Alternately, or in addition, the plate may be made from orcoated with a fibrous material, such as micro filaments, to assist inretaining dirt in the cyclone casing. It will be appreciated that, inaccordance with such embodiments, the plate may be disposable.

Water Mist

In accordance with another aspect, which may be used individually orwith any other aspect, a water mist created, preferably, by means ofelectrostatically and/or mechanically atomization can be placed upstreamof a cyclonic embodiment described herein or any cyclonic separationmeans known in the art to create a humidification means wherein theparticles which do not become collected are cyclonically removed fromthe fluid flow stream. Optionally, one or more or a combination of thecyclonic embodiments described in this specification or any cyclonicseparation means known in the art may be placed upstream of the mistsource to prevent airborne particles from contaminating or otherwiseinterfering with the operation of the mist source.

The water, which does not evaporate, may be recirculated though a filterand/or ozone disinfection and oxidation system and/or ultra violet lightdisinfection system before it is reused in the atomization process. Ifozonated water is used to create the mist, air disinfection can beachieved before a down stream cyclone separator is employed to removethe remaining ozonated water droplets from the air stream.

It is also understood that ozone gas can be introduced into an airstream to oxidize pollutants and to disinfect airborne particlesupstream and that the down stream cyclone separator can remove oxidizedparticles and that if optionally, an electrostatic and/or mechanicalatomization mist source is employed, the ozone gas can be captured inthe water droplets and the water droplets can be removed by means of adown stream cyclone separator.

The improvements may be used in a single application, or individually orin sub-combinations. In particular, the improvements in the design ofcyclones and arrays of cyclones may be used in a single application, orindividually or in sub-combinations. For example, one or more of theimprovements may be used in a single vacuum cleaner. The improvementswhich are selected may be determined based on the degree of particulateremoval which is required, whether a pre and/or post motor filter isutilized, the amount of back pressure which may be produced by the airflow path through the vacuum cleaner, the power of the suction motor andthe like.

It will be appreciated that various modifications and alterations of theembodiments known herein may be made and each is within the scope of thefollowing claims.

1. A surface cleaning apparatus comprising: (a) a dirt inlet; (b) ahandle; (c) a cyclonic cleaning unit comprising a plurality of cyclonesand at least one dirt collection chamber, each of the plurality ofcyclones having an outer wall, an interior, a fluid inlet downstreamfrom the dirt inlet and a fluid outlet; (d) the at least one dirtcollection chamber having an outer wall and an interior, wherein thesurface cleaning apparatus is constructed such that the interior of theat least one dirt collection chamber is visible from a position exteriorto the surface cleaning apparatus; and, (e) a fluid flow motor.
 2. Thesurface cleaning apparatus of claim 1 wherein the outer wall of the atleast one dirt collection chamber has at least a transparent portion. 3.The surface cleaning apparatus of claim 2 wherein the at least one dirtcollection chamber has a maximum recommended dirt capacity and thetransparent portion extends downwardly from a position defining themaximum recommended dirt capacity.
 4. The surface cleaning apparatus ofclaim 2 wherein the at least one dirt collection chamber has a maximumrecommended dirt capacity and the outer wall of the at least one dirtcollection chamber is opaque above a position defining the maximumrecommended dirt capacity.
 5. The surface cleaning apparatus of claim 2wherein the outer wall of the at least one dirt collection chamber is anouter wall of the surface cleaning apparatus.
 6. The surface cleaningapparatus of claim 2 wherein the surface cleaning apparatus furthercomprises a wall positioned exterior to the outer wall of the at leastone dirt collection chamber, at least a sufficient portion of which istransparent to permit a user to view the transparent portion of theouter wall of the at least one dirt collection chamber.
 7. The surfacecleaning apparatus of claim 6 wherein all of the outer wall of the atleast one dirt collection chamber is transparent.
 8. The surfacecleaning apparatus of claim 7 wherein the surface cleaning apparatusfurther comprises a transparent wall positioned radially outwardly ofthe outer wall of the at least one dirt collection chamber.
 9. Thesurface cleaning apparatus of claim 1 wherein each of the plurality ofcyclones has an associated dirt collection chamber.
 10. The surfacecleaning apparatus of claim 9 wherein each of the associated dirtcollection chambers has an outer wall, at least a portion of which istransparent.
 11. The surface cleaning apparatus of claim 9 wherein eachof the associated dirt collection chambers has a bottom that isopenable.
 12. The surface cleaning apparatus of claim 1 wherein each ofthe plurality of cyclones has a plate positioned to substantially dividethe cyclone separator into a cyclone chamber and a dirt collectionchamber.
 13. The surface cleaning apparatus of claim 1 wherein thesurface cleaning apparatus has at least first and second cyclonic stagesand the cyclonic cleaning unit comprises the second cyclonic stage. 14.The surface cleaning apparatus of claim 13 wherein the first and secondcyclonic stages are each separately removable from the surface cleaningapparatus.
 15. The surface cleaning apparatus of claim 13 wherein thefirst cyclonic stage comprises a single cyclone.
 16. The surfacecleaning apparatus of claim 13 wherein the first cyclonic stagecomprises a plurality of cyclones in parallel.
 17. The surface cleaningapparatus of claim 16 wherein the plurality of cyclones of the firstcyclonic cleaning unit have at least one first stage dirt collectionchamber, the at least one first stage dirt collection chamber having afirst stage outer wall and a first stage interior, wherein the surfacecleaning apparatus is constructed such that the first stage interior isvisible from a position exterior to the surface cleaning apparatus. 18.The surface cleaning apparatus of claim 1 wherein at least a portion ofthe outer wall of each of the cyclones is transparent.
 19. The surfacecleaning apparatus of claim 1 wherein the outer wall of each of thecyclones is transparent.
 20. The surface cleaning apparatus of claim 18wherein the portion of the outer walls of the cyclones form an outerwall of the surface cleaning apparatus.
 21. The surface cleaningapparatus of claim 18 wherein the surface cleaning apparatus furthercomprises a wall positioned exterior to the outer wall of the cyclones,at least a sufficient portion of which is transparent to permit a userto view the transparent portion of the outer wall of the cyclones. 22.The surface cleaning apparatus of claim 9 wherein each cyclone andassociated dirt collection chamber is integrally molded from transparentplastic.
 23. The surface cleaning apparatus of claim 22 wherein theouter walls of the dirt collection chambers are a portion of an outersurface of the surface cleaning apparatus and the transparent plastic ofthe cyclone is treated to render the sidewalls of the cyclones opaque.24. The surface cleaning apparatus of claim 22 wherein the surfacecleaning apparatus further comprises a wall positioned exterior to thecyclonic cleaning unit, at least a sufficient portion of which istransparent to permit a user to view the interior of only the dirtcollection chambers.
 25. The surface cleaning apparatus of claim 1further comprising a header in fluid flow communication with the fluidoutlets from the cyclones wherein the header is transparent.
 26. Thesurface cleaning apparatus of claim 1 further comprising a filterhousing, at least a portion of which is transparent.
 27. The surfacecleaning apparatus of claim 26 wherein the transparent portion of thefilter housing is visible when the vacuum cleaner is in use.
 28. Thesurface cleaning apparatus of claim 13 further comprising a filterhousing, at least a portion of which is transparent wherein thetransparent portion of the filter housing is visible when at least oneof the cyclonic stages is removed.
 29. A surface cleaning apparatuscomprising: (a) a dirt inlet; (b) a handle; (c) at least one cycloniccleaning stage; (d) a filter housing, at least a portion of which istransparent; and, (e) a fluid flow motor.
 30. The surface cleaningapparatus of claim 29 wherein the transparent portion of the filterhousing is visible when the vacuum cleaner is in use.
 31. The surfacecleaning apparatus of claim 29 wherein the cyclonic cleaning stage isremovable from the surface cleaning apparatus and the transparentportion of the filter housing is visible when the cyclonic cleaningstage is removed.
 32. The surface cleaning apparatus of claim 29 furthercomprising an openable door and the transparent portion of the filterhousing is visible when the door is open.
 33. The surface cleaningapparatus of claim 29 wherein the filter is a pre-motor filter.
 34. Thesurface cleaning apparatus of claim 29 wherein all of the filter housingis transparent.
 35. The surface cleaning apparatus of claim 29 whereinthe surface cleaning apparatus has at least first and second cycloniccleaning stages.
 36. The surface cleaning apparatus of claim 35 whereinthe first and second cyclonic cleaning stages are each separatelyremovable from the surface cleaning apparatus.
 37. The surface cleaningapparatus of claim 35 wherein the first cyclonic cleaning stagecomprises a single cyclone.
 38. The surface cleaning apparatus of claim35 wherein at least one cyclonic cleaning stage comprises a plurality ofcyclones in parallel.